\documentclass[11pt]{article}

%% \usepackage{scicite}
\usepackage{cell}

\RequirePackage{times}

%% \RequirePackage{fullpage}

\topmargin 0.0cm
\oddsidemargin 0.2cm
\textwidth 16cm 
\textheight 21cm
\footskip 1.0cm


\RequirePackage{ifthen}
\usepackage[affil-it]{authblk}
\usepackage{graphicx}
\usepackage[space]{grffile}
\usepackage{latexsym}
\usepackage{amsfonts,amsmath,amssymb}
\usepackage{url}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\hypersetup{colorlinks=false,pdfborder={0 0 0}}
\usepackage{textcomp}
\usepackage{longtable}
\usepackage{multirow,booktabs}
\usepackage{setspace}

\usepackage{pdfpages}

\usepackage[font=footnotesize,skip=10pt,labelformat=empty]{caption}

%% \usepackage[pagewise]{lineno}
%% \linenumbers

% Avoid section numbers
\setcounter{secnumdepth}{0}

%% Some style parameters
\setlength{\parindent}{0pt}
\setlength{\parskip}{15pt}
\renewcommand{\spacing}[1]{\renewcommand{\baselinestretch}{#1}\normalsize}
\spacing{1.5}

%% Redefine \maketitle for Nature style
\def\@maketitle{%
  \newpage\spacing{1}\setlength{\parskip}{12pt}%
    {\Large\bfseries\noindent\sloppy \textsf{\@title} \par}%
    {\noindent\sloppy \@author}%
}

%% Define the affiliations environment, list each institution as an \item
%% Put after \maketitle
\newenvironment{affiliations}{%
    \setcounter{enumi}{1}%
    \setlength{\parindent}{0in}%
    \slshape\sloppy%
    \begin{list}{\upshape$^{\arabic{enumi}}$}{%
        \usecounter{enumi}%
        \setlength{\leftmargin}{0in}%
        \setlength{\topsep}{0in}%
        \setlength{\labelsep}{0in}%
        \setlength{\labelwidth}{0in}%
        \setlength{\listparindent}{0in}%
        \setlength{\itemsep}{0ex}%
        \setlength{\parsep}{0in}%
        }
    }{\end{list}\par\vspace{12pt}}


\makeatletter

%% Redefine the abstract environment to be the first bold paragraph
\renewenvironment{abstract}
 {\begin{center}
  \bfseries \abstractname\vspace{-.5em}\vspace{0pt}
  \end{center}
  \list{}{%
    \setlength{\leftmargin}{0mm}% <---------- CHANGE HERE
    \setlength{\rightmargin}{\leftmargin}%
  }%
  \item\relax}
 {\endlist}

\renewenvironment{abstract}{%
    \setlength{\parindent}{0in}%
    \setlength{\parskip}{0in}%
    \bfseries%
}{\par\vspace{-6pt}}

%% Redefine the \section command.
\renewcommand{\section}{\@startsection{section}{1}{0pt}%
   {-6pt}{1pt}%
   {\bfseries}%
   }
\renewcommand{\subsection}{\@startsection{subsection}{2}{0pt}%
   {-0pt}{-0.5em}%
   {\bfseries}%
   }

\renewcommand\section{\@startsection%
  {section}{1}{\z@}%      %name, level, indent
  {-6pt}%       %beforeskip
  {.5pt}%     %afterskip
  {\bfseries}  %bold, uppercase
}
\renewcommand\subsection{\@startsection%
  {subsection}{2}{\z@}%      %name, level, indent
  {-0pt}%       %beforeskip
  {.5pt}%     %afterskip
  {\bfseries}  %bold, uppercase
}

\newcommand{\lt}{<}
\newcommand{\gt}{>}
% \newcommand{\ge}{≥}
% \newcommand{\le}{≤}

%% Redefine the figure and table environments.
%% The new figure environment defers printing of all figure captions
%% until the end of the document and prints them in sans serif font.
%% The \includegraphics command is ignored since Nature wants figures
%% as separate files.
%% The table environment was just changed to print on a separate page in
%% sans serif font.  Tables should all be moved to the end of the document
%% manually.  

    
%% \newcommand{\NAT@figcaption}[2][]{\AtEndDocument{
%%     \refstepcounter{figure}
%%     \ifthenelse{\value{figure}=1}{
%%         \newpage\noindent
%%     }{
%%         \par\vfill
%%     }
%%     \noindent\sffamily\hspace{1em}#2}
%%     }

%% \renewenvironment{figure}{\let\caption\NAT@figcaption}{}


% The following lines set up an environment for the last note in the
% reference list, which commonly includes acknowledgments of funding,
% help, etc.  It's intended for users of BibTeX or the {thebibliography}
% environment.  Users who are hand-coding their references at the end
% using a list environment such as {enumerate} can simply add another
% item at the end, and it will be numbered automatically.

\newcounter{lastnote}
\newenvironment{scilastnote}{%
\section{\textbf{ACKNOWLEDGMENTS}}
\setcounter{lastnote}{\value{enumiv}}%
\addtocounter{lastnote}{+1}%
\begin{list}%
%% {\arabic{lastnote}.}
{\setlength{\leftmargin}{.22in}}
{\setlength{\labelsep}{.5em}}}
{\end{list}}

%% %% %% \renewenvironment{table}{\@float{table}[p]\sffamily}{\end@float}

%% ignore all \includegraphics commands in the document
%% \AtBeginDocument{\let\includegraphics\NAT@ignore}

%% \newcommand{\NAT@ignore}[2][]{}


\makeatother



\makeatletter
\renewenvironment{thebibliography}[1]
{\section{\refname}% <--- outcommented
\@mkboth{\MakeUppercase\refname}{\MakeUppercase\refname}%
\list{\@biblabel{\@arabic\c@enumiv}}%
{\settowidth\labelwidth{\@biblabel{#1}}%
\leftmargin\labelwidth
\advance\leftmargin\labelsep
\@openbib@code
\usecounter{enumiv}%
\let\p@enumiv\@empty
\renewcommand\theenumiv{\@arabic\c@enumiv}}%
\sloppy
\clubpenalty4000
\@clubpenalty \clubpenalty
\widowpenalty4000%
\sfcode`\.\@m}
{\def\@noitemerr
{\@latex@warning{Empty `thebibliography' environment}}%
\endlist}
\makeatother

%% References title
%% \renewcommand\refname{\textbf{References and Notes}}


