Abstract:
Background Neuropsychiatric systemic lupus erythematosus (NP-SLE) presents with a wide variety of clinical manifestations, which is often difficult to diagnose with a high mortality. This study aims to investigate the clinical features of NP-SLE involving the central nervous system (CNS) and the differential diagnoses between CNS NP-SLE and intracranial infections. Methods The clinical manifestations, serum immunological features, cerebrospinal fluid (CSF) examinations (including intracranial pressure, leukocyte count, protein, glucose and chloride), CT and (or) MRI and electroencephalogram (EEG) data of 23 NP-SLE patients with CNS involved were retrospectively reviewed. Results Nine patients presented with diffuse manifestations, while 14 patients presented with focal manifestations. Serum analysis showed the positive rates of immunoglobulins anti-nuclear antibody (ANA), anti-double stranded DNA antibody (dsDNA), anti-Sm, anti-ribosmal P protein, anti-SSA and anti-SSB antibodies were 21/22, 7/22, 1/14, 2/14, 9/14 and 3/14 respectively. Patients with decreased serum C3 accounted for 14/20 while patients with decreased serum C4 accounted for 5/20. Besides, patients with increased CSF leukocyte count and microalbumin took up 5/12 and 7/12, while patients with decreased glucose and chloride levels took up 5/12 and 6/12. All 23 patients presented abnormal CT and (or) MRI and 6 patients presented abnormal EEG. Conclusion Serum immunological levels, CT and (or) MRI and EEG examinations contributed to the diagnosis of NP-SLE involving CNS. Although CSF analyses were slightly abnormal, the increase of leukocyte count and average microalbumin was not obvious, and the mean values of glucose and chloride were in the normal range, suggesting that the CSF examinations were helpful for the differential diagnoses from intracranial infections. Glucocorticoids and immunosuppressive drugs were remarkably effective for CNS NP-SLE patients.

Abstract:
Suppose $M$ is a complete n-dimensional manifold, $n\ge 2$, with a metric $\bar{g}_{ij}(x,t)$ that evolves by the Ricci flow $\partial_t \bar{g}_{ij}=-2\bar{R}_{ij}$ in $M\times (0,T)$. For any $0

0$, we will prove the existence of a $\Cal{L}_p$-geodesic which minimize the $\Cal{L}_p(q,\bar{\tau})$-length between $p_0$ and $q$ for any $\bar{\tau}>0$. This result for the case $p=1/2$ is conjectured and used many times but no proof of it was given in Perelman's papers on Ricci flow. My result is new and answers in affirmative the existence of such $\Cal{L}$-geodesic minimizer for the $L_p(q,\tau)$-length which is crucial to the proof of many results in Perelman's papers on Ricci flow. We also obtain many other properties of the generalized $\Cal{L}_p$-geodesic and generalized reduced volume.

Abstract:
Let M be a compact n-dimensional manifold, $n\ge 2$, with metric g(t) evolving by the Ricci flow $\partial g_{ij}/\partial t=-2R_{ij}$ in (0,T) for some $T\in\Bbb{R}^+\cup\{\infty\}$ with $g(0)=g_0$. Let $\lambda_0(g_0)$ be the first eigenvalue of the operator $-\Delta_{g_0} +\frac{R(g_0)}{4}$ with respect to g_0. We extend a recent result of R. Ye and prove uniform logarithmic Sobolev inequality and uniform Sobolev inequalities along the Ricci flow for any $n\ge 2$ when either $T<\infty$ or $\lambda_0(g_0)>0$. As a consequence we extend Perelman's local $\kappa$-noncollapsing result along the Ricci flow for any $n\ge 2$ in terms of upper bound for the scalar curvature when either $T<\infty$ or $\lambda_0(g_0)>0$.

Abstract:
Let $(M,g(t))$, $0\le t\le T$, $\partial M\ne\phi$, be a compact $n$-dimensional manifold, $n\ge 2$, with metric $g(t)$ evolving by the Ricci flow such that the second fundamental form of $\partial M$ with respect to the unit outward normal of $\partial M$ is uniformly bounded below on $\partial M\times [0,T]$. We will prove a global Li-Yau gradient estimate for the solution of the generalized conjugate heat equation on $M\times [0,T]$. We will give another proof of Perelman's Li-Yau-Hamilton type inequality for the fundamental solution of the conjugate heat equation on closed manifolds without using the properties of the reduced distance. We will also prove various gradient estimates for the Dirichlet fundamental solution of the conjugate heat equation.

Abstract:
In this paper we will prove a maximum principle for the solutions of linear parabolic equation on complete non-compact manifolds with a time varying metric. We will prove the convergence of the Neumann Green function of the conjugate heat equation for the Ricci flow in $B_k\times (0,T)$ to the minimal fundamental solution of the conjugate heat equation as $k\to\infty$. We will prove the uniqueness of the fundamental solution under some exponential decay assumption on the fundamental solution. We will also give a detail proof of the convergence of the fundamental solutions of the conjugate heat equation for a sequence of pointed Ricci flow $(M_k\times (-\alpha,0],x_k,g_k)$ to the fundamental solution of the limit manifold as $k\to\infty$ which was used without proof by Perelman in his proof of the pseudolocality theorem for Ricci flow.

Abstract:
We give a simple proof of an extension of the existence results of Ricci flow of G.Giesen and P.M.Topping [GiT1],[GiT2], on incomplete surfaces with bounded above Gauss curvature without using the difficult Shi's existence theorem of Ricci flow on complete non-compact surfaces and the pseudolocality theorem of G.Perelman [P1] on Ricci flow. We will also give a simple proof of a special case of the existence theorem of P.M.Topping [T] without using the existence theorem of W.X.Shi [S1].

Abstract:
For any $n\ge 3$, $00$, $\beta>0$, $\alpha$, satisfying $\alpha\le\beta(n-2)/m$, we prove the existence of radially symmetric solution of $\frac{n-1}{m}\Delta v^m+\alpha v +\beta x\cdot\nabla v=0$, $v>0$, in $\R^n$, $v(0)=\eta$, without using the phase plane method. When $00$, we prove that the radially symmetric solution $v$ of the above elliptic equation satisfies $\lim_{|x|\to\infty}\frac{|x|^2v(x)^{1-m}}{\log |x|} =\frac{2(n-1)(n-2-nm)}{\beta(1-m)}$. In particular when $m=\frac{n-2}{n+2}$, $n\ge 3$, and $\alpha=2\beta/(1-m)>0$, the metric $g_{ij}=v^{\frac{4}{n+2}}dx^2$ is the steady soliton solution of the Yamabe flow on $\R^n$ and we obtain $\lim_{|x|\to\infty}\frac{|x|^2v(x)^{1-m}}{\log |x|}=\frac{(n-1)(n-2)}{\beta}$. When $0\max (\alpha,0)$, we prove that $\lim_{|x|\to\infty}|x|^{\alpha/\beta}v(x)=A$ for some constant $A>0$. For $\beta>0$ or $\alpha=0$, we prove that the radially symmetric solution $v^{(m)}$ of the above elliptic elliptic equation converges uniformly on every compact subset of $\R^n$ to the solution $u$ of the equation $(n-1)\Delta\log u+\alpha u+\beta x\cdot\nabla u=0$, $u>0$, in $\R^n$, $u(0)=\eta$, as $m\to 0$.

Abstract:
We will give a simple proof that the metric of any compact Yamabe gradient soliton (M,g) is a metric of constant scalar curvature when the dimension of the manifold n>2.