We study the Helmholtz equation with periodic coefficients in a closed wave-guide. A functional analytic approach is used to formulate and to solve the radiation problem in a self-contained exposition. In this context, we simplify the non-degeneracy assumption on the frequency. Limiting absorption principles (LAPs) are studied and the radiation condition corresponding to the chosen LAP is derived; we include an example to show different LAPs lead, in general, to different solutions of the radiation problem. Finally, we characterize the set of all bounded solutions to the homogeneous problem.

An implicit variable-step BDF2 scheme is established for solving the space fractional Cahn-Hilliard equation derived from a gradient flow in the negative order Sobolev space H − α , α∈(0 ,1). The Fourier pseudo-spectral method is applied for the spatial approximation. The space fractional Cahn-Hilliard model poses significant challenges in theoretical analysis for variable time-stepping algorithms compared to the classical model, primarily due to the introduction of the fractional Laplacian. This issue is settled by developing a general discrete Hölder inequality involving the discretization of the fractional Laplacian. Subsequently, the unique solvability and the modified energy dissipation law are theoretically guaranteed. We further rigorously provided the convergence of the fully discrete scheme by utilizing the newly proved discrete Young-type convolution inequality to deal with the nonlinear term. Numerical examples with various interface widths and mobility are conducted to show the accuracy and the energy decay for different orders of the fractional Laplacian. In particular, we demonstrate that the adaptive time-stepping strategy, compared with the uniform time steps, captures the multiple time scales evolutions of the solution in simulations.

Atmospheric rivers (ARs) are an important component of the global water cycle, and AR-related hydrological hazards are across the midlatitudes, including New Zealand. The ability to classify the strength and potential impact of ARs has shown benefits to water resource management in western U.S. regions. In New Zealand, the topography means that the impact of ARs may vary significantly on either side of mountainous areas. In this study, we evaluate whether ARs dominate monthly heavy rainfall events and investigate characteristics of AR events that contribute to heavy rainfall as well as the performance of an AR impact ranking scale concerning orientations for these AR events. We found that different geographical regions favour ARs with different orientations for heavy rainfall generation, and northwesterly ARs are more likely to deliver higher rainfall at certain classification levels. Furthermore, we showed cases where ARs classified at the level could result in different benefits and hazards in different locations. Future research should focus on a more descriptive AR ranking scale regarding hydrometeorological benefits and hazards, considering factors such as the correspondence cyclones and topography.

To explore the forensic application of neuroimaging-based concealed information test (CIT) with combined multiple measurements, the simultaneously recorded data of functional near-infrared spectroscopy (fNIRS), skin conductance responses (SCRs), heart rate (HR), and reaction time (RT) is collected in order to detect participants’ concealed information in a standard CIT with a mock crime scenario. We hypothesized the fNIRS-based neuroimaging data could successfully detect deception, and the combination of multiple indicators could integrate multidimensional information triggered by deception, thus providing enhanced efficiency in deception detection. The results validated the hypotheses that fNIRS-based neuroimaging data could effectively discriminate between guilty and innocent participants after a mock crime. Furthermore, the use of multiple indicators resulted in a much higher detection efficiency (AUC = 0.96 with fNIRS channel 8) compared to the use of a single indicator (AUC = 0.66-0.86). These results illustrate the potential of the combination of fNIRS and multiple indicators for deception detection with a mock crime scenario and further facilitate the forensic application of fNIRS-based CIT.

Objective This retrospective cohort study aimed to identify reasons and risk factors associated with 30-day readmission after otolaryngology-head and neck surgery and propose preventive measures. Design The study was conducted at a large single academic tertiary care center in China, analyzing cases of inpatient otolaryngology-head and neck surgery from August 2019 to December 2021. Setting The study was conducted in a large tertiary-care hospital in China. Participants The study included adult patients who underwent otolaryngology-head and neck surgery and experienced 30-day readmissions. Main outcome measures The main outcome measured was the analysis of 30-day readmissions for adult patients after otolaryngology-head and neck surgery. Results A total of 7,608 otolaryngology-head and neck surgery patients were identified, with 0.85% and 0.84% experiencing unplanned and planned readmissions within 30 days, respectively. Patients with unplanned readmissions were older and had a longer length of stay compared to those with planned readmissions and those without readmissions. Old age and length of stay were identified as risk factors for unplanned readmission. The most common reasons for unplanned and planned readmissions were surgical complications and surgical cancellations, respectively. Conclusions Analyzing the causes and risk factors for 30-day readmissions after otolaryngology-head and neck surgery can guide perioperative planning and help prevent readmissions, leading to improved patient outcomes.

Continuous space species distribution models (SDMs) have a long-standing history as a valuable tool in ecological statistical analysis. Geostatistical and preferential models are both common models in ecology. Geostatistical models are employed when the process under study is independent of the sampling locations, while preferential models are employed when sampling locations are dependent on the process under study. But, what if we have both types of data collectd over the same process? Can we combine them? If so, how should we combine them? This study investigated the suitability of both geostatistical and preferential models, as well as a mixture model that accounts for the different sampling schemes. Results suggest that in general the preferential and mixture models have satisfactory and close results in most cases, while the geostatistical models presents systematically worse estimates at higher spatial complexity, smaller number of samples and lower proportion of completely random samples.

Introduction:Sheehan’s syndrome is a rare disorder characterized by pituitary gland necrosis following severe postpartum haemorrhage. The primary cause is an ischemic insult to the pituitary gland due to hypoperfusion during childbirth. This leads to tissue necrosis and subsequent hormone deficiencies. We present a case of Sheehan’s syndrome in a patient who exhibited multiple hormone deficiencies and responded well to hormone replacement therapy.

Cyclic loading affects the mechanic characteristics and long-term stability of geotechnical engineering. Although the fatigue failure and weakening effect of cyclic load have been extensively studied, the strengthening effect and its failure mechanism are somewhat unclear. In this study, a series of cyclic-to-monotonic loading tests with the upper limit in elastic deformation stages was conducted on siltstone. Results show that the siltstone in the test is a typical porous weakly cemented rock, and its characteristic stress can be determined by volume strain curve, AE counts and ultrasonic velocity. The strengthening and weakening effects of siltstone under cyclic loading depend on the upper limit of cyclic load. When the upper limit of cyclic load is in the elastic deformation stage, the strength, elastic modulus, and characteristic stress of siltstone were improved significantly. The microscopic mechanism of strengthening effect was analysed through AE b-value, sources, and electron microscopy scanning. Under the uniaxial compression, the evolution law of AE sources shows a specifically spatio-temporal zonal disintegration phenomenon. The essential reasons for the strengthening effect are mainly reflected that the micro fracture mode was changed. Under the cyclic load test, the spatial distribution of AE sources of siltstone is more uniform, which indicates the skeleton area of the specimen which can bear the axial load increased. However, the burst of AE signals is delayed, and the crack scale is small due to the strengthening effect. The difficulty of geotechnical engineering disaster prediction and prevention was greatly increase, and the attention should be paid to similar geotechnical engineering.

Objectives: Existing knowledge on Health Related Quality of Life (HRQoL) after surgical removal of sinonasal inverted papilloma (IP) is limited. Moreover, predictors for a better or worse postoperative HRQoL outcome are not known. Our aim was to assess HRQoL in all three health domains (physical, psychological and social), track its postoperative trajectory, investigate if preoperative observations could predict distinct postoperative HRQoL outcomes, and evaluate whether physicians’ interventions could contribute to improved postoperative HRQoL. Design: Prospective cohort study. Setting: Tertiary referral hospital. Participants: Seventy-four patients who underwent surgery for an IP were included. They were asked to fill in the Endonasal Endoscopic Sinus and Skull Base Surgery Questionnaire (EES-Q) preoperatively, and then two weeks, three months, and one year postoperatively. Main outcome measures: Linear mixed models (LMM) analyses were performed to evaluate the overall postoperative HRQoL and the separate health domains, as well as the impact of specific variables (sex, age, ASA classification, smoker, Krouse staging, preoperative EES-Q score, type of surgery and postoperative antibiotics) on HRQoL improvement. Results: The total EES-Q score (P<.001) as well as the physical (P<.001), psychological (P=.049), and the social (P=.002) domains significantly improved postoperatively. ASA classification (P=.049), preoperative EES-Q score (P<.001) and postoperative antibiotics (P=.036) were significant variables. Conclusions: Overall HRQoL, as well as each of the three health domains, improved significantly. A higher ASA score, a higher preoperative EES-Q score, and the administration of postoperative antibiotics were significant predictors for better HRQoL recovery postoperatively. Further research is necessary to confirm these results.

This study aimed to investigate the relationship between MHR and coronary artery lesions. A total of 488 patients aged 40-84 years who had undergone coronary angiography were enrolled in the study. The patients were divided into groups based on the presence or absence of coronary artery lesions and the number of branches affected. Statistical analysis using SPSS 26.0 software was conducted to examine the relationship between MHR, relevant clinical indicators, and coronary artery lesions. Additionally, the predictive value of MHR for coronary artery lesions was evaluated using the receiver operating characteristic (ROC) curve. The results revealed significantly higher MHR values in the lesioned group compared to the non-lesioned group [0.45 (0.34-0.62) vs. 0.35 (0.26-0.45), P <0.001]. Even after adjusting for various factors such as gender, age, BMI, waist-hip ratio, smoking history, disease history, medication history, and relevant biochemical parameters, MHR remained a significant risk factor for coronary artery lesions (OR=14.041, 95% CI 1.746 to 112.899, P=0.013). The ROC curve analysis determined that an optimal diagnostic threshold of 0.435 for MHR exhibited a sensitivity of 0.546 and a specificity of 0.740 for coronary artery lesions. In conclusion, elevated MHR levels were found to be associated with coronary artery lesions. The study demonstrated that a higher MHR level corresponded to a greater percentage of patients with coronary artery lesions, particularly in cases with a lesion branch number of 3. Therefore, MHR could serve as a valuable tool for identifying individuals at risk of developing coronary artery lesions.

Conventional cancer treatments face the challenge of therapeutic resistance, which causes poor treatment outcomes. The use of combination therapies can improve treatment results in patients and is one of the solutions to overcome this challenge. Chemotherapy is one of the conventional treatments that, due to the non-targeted and lack of specificity in targeting cancer cells, can cause serious complications in the short and long-term for patients by damaging healthy cells. Also, the employment of a wide range of strategies for chemotherapy resistance by cancer cells, metastasis, and cancer recurrence create serious problems to achieve the desired results of chemotherapy. Accordingly, targeted therapies can be used as a combination treatment with chemotherapy to both cause less damage to healthy cells, which as a result, they reduce the side effects of chemotherapy, and by targeting the factors that cause therapeutic challenges, can improve the results of chemotherapy in patients. Small molecules are one of the main targeted therapies that can be used for diverse targets in cancer treatment due to their penetration ability and characteristics. However, small molecules in cancer treatment are facing obstacles that a better understanding of cancer biology, as well as the mechanisms and factors involved in chemotherapy resistance, can lead to the improvement of this type of major targeted therapy. In this review article, at first, the challenges that lead to not achieving the desired results in chemotherapy and how cancer cells can be resistant to chemotherapy are examined, and at the end, research areas are suggested that more focusing on them, can lead to the improvement of the results of using targeted small molecules as an adjunctive treatment for chemotherapy in the conditions of chemotherapy resistance and metastasis of cancer cells.

Many plant species rely upon ants to protect against herbivores. In arid environments, these plants often form stronger bonds with dominant ant species that, in turn, provide a better anti-herbivory defense than low aggressive subordinate ants. Dominant ants typically claim the plants producing more nutritious nectar, commonly leaving less valuable plants to be guarded by lower-quality bodyguards. As water scarcity increases, the value of the extrafloral nectar also increases, which can increase the control of the most valuable plants by dominant ants and of the displacement of outcompeted ants to less valuable plants, reducing niche overlap among ant species and, consequently, the generalization of ant-plant interactions at the community level. To evaluate this hypothesis, we crossed data from 63 empirical ant-plant networks with the mean precipitation rate of the sites and period in which the interactions were sampled. As the environment dries, ant-plant networks decreased in species richness but maintained other network properties. Surprisingly, the decline in the number of ant and plant species engaged in the mutualism along the precipitation gradient increased the interaction generalization in drier habitats. But this increased generalization is possible due to the increase in probability of interaction between all plant and ant species due to the lower richness. Hence, water availability primarily influences ant-plant interactions through its impact on ant and plant communities. This has significant eco-evolutionary consequences, as possibly increasing the persistence of this networks in drier environments, demonstrating a new pathway through which environmental factors can impact ecological interactions.

The retina consists of various cell types arranged in eight cell layers and two membranes that originate from the neuroectodermal cells. The purpose of this study is to evaluate the morphogenesis of the retina by using light and electron microscopy, as well as immunohistochemical techniques. The timing of differentiation and distribution of the cellular component and the layers of the rabbit retina are investigated. There were 32 rabbit embryos and 12 rabbits used. The rabbit retina begins its prenatal development on the tenth day of gestation in the form of optic cup. The process of neuro- and glio-genesis occurs in several stages; in the first stage, the ganglionic cells are differentiated. The second stage includes the differentiation of Muller, amacrine and cone cells. The differentiation of bipolar, horizontal and rod cells consider the late stage of neuro-genesis. All these stages occur during the embryonic period. Then the retina continues its development postnatally by formation of the outer segment of photoreceptor layer and the all layers of the rabbit retina are established. By immunohistochemical studies, the S100 protein is expressed by the Muller cells that locate in the inner nuclear layer and its radiating processes that traverse the retina from the outer to the inner limiting membranes. Concerning to Calretinin, it is labeled within the amacrine cells which occupy the inner nuclear layer and the displaced amacrine cells that locate in the ganglionic cell layer.

Objective: To demonstrate the long-term outcome of a symptom-solving treatment model (SSTM). Design: Observational study between June 2016 and December 2022. Setting: Purohit General Hospital Population: 68 consecutive candidates of hysterectomy for severe pelvic endometriosis. Methods: Candidates were treated by the SSTM, which constitutes a systematic vagino-laparoscopic conservative strategy of hysterectomy with preservation of the ovary or ovaries followed by 24 months of postoperative depot-medroxyprogesterone acetate (DMPA) therapy. Cases were followed up to December 2022, 2.5 years beyond the last hysterectomy in May 2020. Main outcome measures: Relief of endometriosis-associated symptoms and prevention of recurrence in the long term. Results: Symptomatic relief of endometriosis-related pain, such as cyclical dysmenorrhoea, pelvic pain, dyschezia, and vaginal pain, occurred in all 68 (100%) cases from the next expected date of menstruation. None of the cases showed a recurrence of endometriosis-related pelvic pain; overall, 37 (54.41%) cases crossed 4–6 years, and 31 (45.58%) cases crossed 2.5–4.0 years following the hysterectomy operation. Four (5.88%) cases had non-endometriotic pelvic pain. None of the cases required repeat surgery or had any major side effects or complications due to DMPA. No major perioperative complications were observed. The results were achieved without the requirement of challenging extensive retroperitoneal laparoscopic dissection, ureterolysis, and rectum surgeries. Conclusions: This SSTM can be an option in indicated cases of severe pelvic endometriosis to provide symptom relief and prevent the recurrence of endometriosis-associated pelvic pain in the long term.

Purpose: To determine the proportion of Australians dispensed psychotropic medications between 2013 and 2022 according to their age. Methods: Services Australia provided a de-identified 10% random Pharmaceutical Benefits Scheme (PBS) sample that allowed us to determine the proportion of Australians dispensed at least one script per year for the use of antipsychotics, antidepressants, anxiolytics, and hypnotics. The classification of medications followed Anatomical Therapeutic Chemical (ATC) coding. Participants were stratified into 10-year age groups from 0-9 to ≥90 years, and sex was coded as male/female. We used logit models to analyse the data. Results: The number of records per year ranged from 1,540,520 to 1,746,402, and 54.10% were for females. A greater proportion of older adults, particularly those aged ≥70 years, were dispensed antipsychotics, antidepressants, anxiolytics, and hypnotics than any other age-group. The proportion of people dispensed antipsychotics, anxiolytics, and hypnotics declined between 2013 and 2022, but increased for antidepressants, most markedly for adolescents and young adults. Females were more frequently dispensed antidepressants, anxiolytics, and hypnotics than males, but males were more frequently dispensed antipsychotics than females. Conclusions: Older age groups and females are the most frequent recipients of psychotropic medications dispensed in Australia. The organisation and resourcing of health services should reflect this reality.

Purpose: In drug studies, research designs requiring no prior exposure to certain drug classes may restrict important populations. Since abuse-deterrent formulations (ADF) of opioids are routinely prescribed after other opioids, choice of study design, identification of appropriate comparators, and addressing confounding by “indication” are important considerations in ADF post-marketing studies. Methods: In a retrospective cohort study using claims data (2006-2018) from a North Carolina private insurer [NC claims] and Merative MarketScan [MarketScan], we identified patients (18-64 years old) initiating ADF or non-ADF extended-release/long-acting (ER/LA) opioids. We compared patient characteristics and described opioid treatment history between treatment groups, classifying patients as traditional (no opioid claims during prior six-month washout period) or prevalent new users. Results: We identified 8,415 (NC claims) and 147,978 (MarketScan) ADF, and 10,114 (NC claims) and 232,028 (MarketScan) non-ADF ER/LA opioid initiators. Most had prior opioid exposure (ranging 64-74%), and key clinical differences included higher prevalence of recent acute or chronic pain and surgery among patients initiating ADFs compared to non-ADF ER/LA initiators. Concurrent immediate-release opioid prescriptions at initiation were more common in prevalent new users than traditional new users. Conclusions: Careful consideration of the study design, comparator choice, and confounding by “indication” is crucial when examining ADF opioid use-related outcomes.

Type of article (Case Report)different treatment modalities for pulp stonesFouad Brigui1, Amira Kikly1.3, Wided Askri2 ,Ameni Chadlia Belghith1.3 ,Neila Zokkar1 and Nabiha Douki Zbidi1.31 Dental Medicine Department of Sahloul Sousse Hospital, Faculty of Dentistry of Monastir, Tunisia

Each solar cell is characterized at the end-of-line using current-voltage ( IV) measurements, except shingle cells, due to multiplied measurement efforts. Therefore, the respective host cell quality is adopted for all resulting shingles, which is sufficient for samples with laterally homogeneous quality. Yet, for heterogeneous defect distributions, this procedure leads to (i) loss of high quality shingles due to defects on neighboring host cell parts, (ii) increased mismatch losses due to inaccurate binning and (iii) lack of shingle-precise characterization. In spatially resolved host measurements, such as electroluminescence images, all shingles are visible along with their properties. Within a comprehensive experiment 840 hosts and their resulting shingles are measured. Thereafter, a deep learning model has been designed and optimized which processes host-images and determines IV parameters like efficiency or fill factor, IV curves and binning classes for each shingle cell. The efficiency can be determined with an error of 0 .06 % abs enabling a 13 % abs improvement in correct assignment of shingles to bin classes compared to industry standard. This results in lower mismatch losses and higher output power on module level as demonstrated within simulations. Also IV curves of defective and defect-free shingle cells can be derived with good agreement to actual shingle measurements.

Understory assemblages associated with canopy-forming species such as trees, kelps, and rockweeds should respond strongly to climate stressors due to strong interaction strengths. Climate change can directly and indirectly modify these assemblages, particularly during more stressful seasons and climate scenarios. However, fully understanding the seasonal impacts of different climate conditions on canopy-reliant assemblages is difficult due to a continued emphasis on studying single species responses to a single future climate scenario during a single season. To examine these more complex interactions, we used mesocosm experiments to expose intertidal assemblages associated with the canopy-forming golden rockweed, Silvetia compressa, to elevated temperature and pCO2 conditions reflecting two projected greenhouse emission scenarios [RCP 2.6 (low) & RCP 4.5 (moderate)]. Assemblages were grown in the presence and absence of Silvetia, and in two seasons. Relative to ambient conditions, predicted climate scenarios generally suppressed Silvetia biomass and photosynthetic efficiency. However, these effects varied seasonally - both future scenarios reduced Silvetia biomass in summer, but only the moderate scenario did so in winter. These reductions shifted the assemblage, with more extreme shifts occurring in summer. Contrarily, future scenarios did not shift assemblages within Silvetia Absent treatments, suggesting that climate primarily affected assemblages indirectly through changes in Silvetia. Mesocosm experiments were coupled with a field Silvetia-removal experiment to simulate the effects of climate-mediated Silvetia loss on natural assemblages. Consistent with the mesocosm experiment, Silvetia loss resulted in season-specific assemblage shifts, with weaker effects observed in winter. Together, our study supports the hypotheses that climate-mediated changes to canopy-forming species can indirectly affect the associated assemblage, and that these effects vary seasonally. Such seasonality is important to consider as it may provide periods of recovery when conditions are less stressful, especially if we can reduce the severity of future climate scenarios.

In this paper, carbon particles with micro- and nano- particle size were synthesized through a hydrothermal reaction of glucose, namely C-1(123.1 nm), C-2(229.2 nm), C-3(335.1 nm), C-4(456.2 nm) and C-5(534.0 nm) with distinct sizes. We utilized five size carbon particles as individual fillers into the EHS matrix materials to prepare composite eutectic phase change materials (C/EHS PCMs) by melt blending technique. The impact of carbon particle size on the dispersion stability and thermal properties of Na2SO4·10H2O-Na2HPO4·12H2O (EHS) phase change materials was investigated. It is shown that adding 0.2wt% C-2 can decrease the supercooling degree of EHS to 1.5 C. The cyclic stability of C/EHS varies significantly depending on the size of carbon particles. The results of differential scanning calorimetry reveal that the incorporation of C-1, C-2, C-3, and C-4 into EHS lead to an enhancement of latent heat. The latent heat capacity of EHS with 0.2wt% C-2 is 243.4 J·g-1, and after undergoing 500 cycles of solid-liquid phase transition, the latent heat remained above 200 J·g-1. The C-2/EHS composite phase change material holds significant potential for advancing building insulation and solar energy storage technologies.

Urbanization modifies ecosystem conditions and evolutionary processes. This includes air pollution, mostly tropospheric ozone (O3), which leads to urban and peri-urban forest decline. Such is the case of fir (Abies religiosa) forests in the peripheral mountains west of Mexico City, which have been severely affected by O3 pollution since the 1970s. Interestingly, some young individuals with low O3—related damage have been observed within a zone of great O3 incidence, which might suggest rapid tolerance/adaptation to this pollutant. We compared asymptomatic and damaged individuals of the same age (≤15 years old; n = 10) using histological, metabolomic and transcriptomic methods. Plants were sampled during days of high (170 ppb) and moderate (87 ppb) O3 concentration periods. After verifying that all individuals clustered within the same local genetic group when compared to a species-wide panel (Admixture analysis with ~1.5K SNPs), we observed thicker epidermis and more collapsed cells in the palisade parenchyma in needles from damaged than from asymptomatic individuals; such differences increased with needle age. Furthermore, damaged individuals had lower concentrations of various terpenoids (ß-Pinene, ß-Caryophylene Oxide, α-Caryophylene, ß-α-Cubebene and α-Muurolene) than asymptomatic trees, as evidenced through GC-MS. Finally, transcriptomic analyses revealed differential expression for thirteen genes related to carbohydrate metabolism, plant defense, and gene regulation. Our results indicate a rapid and contrasting phenotypic response between plants, likely modeled by standing genetic variation and/or plastic mechanisms. They open the door to future evolutionary studies for understanding how O3 tolerance develops in urban environments, and for identifying tolerant germplasm for forest restoration.

Critically ill patients with infections present with considerable challenges in antimicrobial use due to multiple reasons such as pathophysiological alterations, comorbidities, supportive treatment and the pathogenicity of implicated organism. Fluid shifts, hyperdynamic state, altered renal clearance are the rapid changes which are often not considered while administering antimicrobials. Vital organ dysfunction with or without Multi–Organ Dysfunction Syndrome (MODS) often necessitates use of supportive management in the form of Ventilatory Support or Renal Replacement Therapy (RRT) to Extracorpeal Membrane Oxygenation (ECMO) to name a few. These supportive measures may have implication on PK-PD of administered antimicrobials. Certain patient parameters such as age, weight, comorbid illnesses like cystic fibrosis, burns or immunocompromised state can be important determinants of pharmacokinetics and pharmacodynamics (PK-PD) of antimicrobials. Issues such as bioavailability of the antimicrobial at the primary focus of infection need to be taken into consideration while making choice of antimicrobial(s) and deciding a dose. The critical pharmacodynamic parameters that need to be taken into account consider are disease state, altered bacterial susceptibility, pathogenicity and localization of the organism and host immunity while making decisions about optimized antimicrobial treatment in a critically ill patient with infection. The current review delves on these nuances with a focus on PK-PD for optimized use of antimicrobials in a critically ill patient.

A document by Ellen Yasumiishi. Click on the document to view its contents.

BACKGROUND:Arrhythmia is a common cardiac electrical phenomenon in clinic, and everyone has suffered or experienced different types of arrhythmia in different periods.In spite of the rapid development of modern medicine and the increasingly comprehensive understanding of cardiac electrophysiology, there is still no satisfactory explanation with the mechanism of some arrhythmias.There is no absolute differentiation in tissue cells of any organ, and its biological effect is based on endogenous and exogenous factors, the former is the essence and the latter is the condition.The existence or induction of certain or analogous cardiac pacemaker cells in the area of working cells may be more reasonable to explain autorhythmicity increasing in some conditions. This paper will discuss the topic.