基于灰色关联度与TOPSIS模型分析不同配伍比例的知母对石膏中6种无机元素溶出的影响

目的基于灰色关联度和逼近理想解排序(TOPSIS)法探讨配伍不同比例的知母对石膏中钾(K)、钛(Ti)、锶(Sr)、钡(Ba)、钙(Ca)、镁(Mg)6种无机元素溶出的影响,为临床提供一定参考。方法建立电感耦合等离子体质谱(ICP-MS)法同时分析石膏-知母药对中K、Ti、Sr、Ba、Ca、Mg 6种无机元素含量,并用灰色关联度法和TOPSIS综合分析,与不同比例知母配伍前后,石膏中6种无机元素溶出的变化。结果ICP-MS法测定石膏-知母药对中无机元素的线性、精密度、重复性和稳定性试验结果良好,平均加样回收率为81.78%~104.13%,RSD为2.10%~4.62%(n=6)。与不同比例知母配伍后石膏中6种无机元素的溶出均显著高于石膏单煎(P<0.05),石膏-知母30∶9配伍比例时石膏中6种无机元素溶出得分最高。结论ICP-MS法灵敏度高、准确性好,可用于石膏-知母药对中K、Ti、Sr、Ba、Ca、Mg等6种无机元素的溶出量测定。石膏-知母最佳配伍比例为30∶9时,可有效提高石膏中6种无机元素的溶出,为两者进一步的配伍研究提供依据。

A decellularized nerve matrix scaffold inhibits neuroma formation in the stumps of transected peripheral nerve after peripheral nerve injury

Traumatic painful neuroma is an intractable clinical disease characterized by improper extracellular matrix(ECM)deposition around the injury site.Studies have shown that the microstructure of natural nerves provides a suitable microenvironment for the nerve end to avoid abnormal hyperplasia and neuroma formation.In this study,we used a decellularized nerve matrix scaffold(DNM-S)to prevent against the formation of painful neuroma after sciatic nerve transection in rats.Our results showed that the DNM-S effectively reduced abnormal deposition of ECM,guided the regeneration and orderly arrangement of axon,and decreased the density of regenerated axons.The epineurium-perilemma barrier prevented the invasion of vascular muscular scar tissue,greatly reduced the invasion ofα-smooth muscle actin-positive myofibroblasts into nerve stumps,effectively inhibited scar formation,which guided nerve stumps to gradually transform into a benign tissue and reduced pain and autotomy behaviors in animals.These findings suggest that DNM-S-optimized neuroma microenvironment by ECM remodeling may be a promising strategy to prevent painful traumatic neuromas.

Tissue engineering for the repair of peripheral nerve injury

Peripheral nerve injury is a common clinical problem and affects the quality of life of patients. Traditional restoration methods are not satisfactory. Researchers increasingly focus on the field of tissue engineering. The three key points in establishing a tissue engineering material are the biological scaffold material, the seed cells and various growth factors. Understanding the type of nerve injury, the construction of scaffold and the process of repair are necessary to solve peripheral nerve injury and promote its regeneration. This review describes the categories of peripheral nerve injury, fundamental research of peripheral nervous tissue engineering and clinical research on peripheral nerve scaffold material, and paves a way for related research and the use of conduits in clinical practice.

Disease-specific mi R-34a as diagnostic marker of nonalcoholic steatohepatitis in a Chinese population

AIM To assess disease-specific circulating micro RNAs(mi RNAs) in non-alcoholic steatohepatitis(NASH) patients.METHODS A total of 111 biopsy-proven non-alcoholic fatty liver disease(NAFLD) or chronic hepatitis B(CHB) patients and healthy controls from China's Mainland were enrolled to measure their serum levels of mi R-122,-125 b,-146 b,-16,-21,-192,-27 b and-34 a. The correlations between serum mi RNAs and histological features of NAFLD were determined. The diagnostic value of mi RNA in NASH and significant fibrosis was analyzed and compared with that of cytokeratin-18(CK-18), fibrosis-4(FIB-4), and aspartate aminotransferase to platelet ratio index(APRI), respectively.RESULTS Circulating mi R-122,-16,-192 and-34 a showed differential expression levels between NAFLD and CHB patients, and mi R-34 a had an approximately 2-fold increase in NAFLD samples compared with that of CHB samples(P < 0.01). Serum mi R-122,-192 and-34a levels were correlated with steatosis(R = 0.302, 0.323 and 0.470, respectively, P < 0.05) and inflammatory activity(R = 0.445, 0.447 and 0.517, respectively, P < 0.01); only serum mi R-16 levels were associated with fibrosis(R = 0.350, P < 0.05) in patients with NAFLD. The diagnostic value of mi R-34 a for NASH(area under the receiver operating characteristic, 0.811, 95%CI: 0.670-0.953) was superior to that of alanine aminotransferase, CK-18, FIB-4 and APRI in NAFLD, but mi R-16 showed a limited performance in the diagnosis of significant fibrosis in NASH.CONCLUSION Circulating mi R-34 a may serve as a disease-specific noninvasive biomarker for the diagnosis of NASH.

Trimethylamine N-oxide attenuates high-fat high-cholesterol dietinduced steatohepatitis by reducing hepatic cholesterol overload in rats

BACKGROUND Trimethylamine N-oxide (TMAO) has been shown to be involved in cardiovascular disease (CVD). However, its role in nonalcoholic steatohepatitis (NASH) is unknown. AIM To determine the effect of TMAO on the progression of NASH. METHODS A rat model was induced by 16-wk high-fat high-cholesterol (HFHC) diet feeding and TMAO was administrated by daily oral gavage for 8 wk. RESULTS Oral TMAO intervention attenuated HFHC diet-induced steatohepatitis in rats. Histological evaluation showed that TMAO treatment significantly alleviated lobular inflammation and hepatocyte ballooning in the livers of rats fed a HFHC diet. Serum levels of alanine aminotransferase and aspartate aminotransferase were also decreased by TMAO treatment. Moreover, hepatic endoplasmic reticulum (ER) stress and cell death were mitigated in HFHC diet-fed TMAOtreated rats. Hepatic and serum levels of cholesterol were both decreased by TMAO treatment in rats fed a HFHC diet. Furthermore, the expression levels of intestinal cholesterol transporters were detected. Interestingly, cholesterol influxrelated Niemann-Pick C1-like 1 was downregulated and cholesterol efflux-related ABCG5/8 were upregulated by TMAO treatment in the small intestine. Gut microbiota analysis showed that TMAO could alter the gut microbial profile and restore the diversity of gut flora. CONCLUSION These data suggest that TMAO may modulate the gut microbiota, inhibit intestinal cholesterol absorption, and ameliorate hepatic ER stress and cell death under cholesterol overload, thereby attenuating HFHC diet-induced steatohepatitis in rats. Further studies are needed to evaluate the influence on CVD and define the safe does of TMAO treatment.

mi R-192-5p regulates lipid synthesis in non-alcoholic fatty liver disease through SCD-1

AIM To evaluate the levels of mi R-192-5 p in non-alcoholic fatty liver disease(NAFLD) models and demonstrate the role of mi R-192-5 p in lipid accumulation. METHODS Thirty Sprague Dawley rats were randomly divided into three groups, which were given a standard diet, a high-fat diet(HFD), and an HFD with injection of liraglutide. At the end of 16 weeks, hepatic mi R-192-5 p and stearoyl-Co A desaturase 1(SCD-1) levels were measured. Mi R-192-5 p mimic and inhibitor and SCD-1 si RNA were transfected into Huh7 cells exposed to palmitic acid(PA). Lipid accumulation was evaluated by oil red O staining and triglyceride assays. Direct interaction was validated by dual-luciferase reporter gene assays.RESULTS The HFD rats showed a 0.46-fold decrease and a 3.5-fold increase in hepatic mi R-192-5 p and SCD-1 protein levels compared with controls, respectively, which could be reversed after disease remission by liraglutide injection(P < 0.01). The Huh7 cells exposed to PA also showed down-regulation and up-regulation of mi R-192-5 p and SCD-1 protein levels, respectively(P < 0.01). Transfection with mi R-192-5 p mimic and inhibitor in Huh7 cells induced dramatic repression and promotion of SCD-1 protein levels, respectively(P < 0.01). Luciferase activity was suppressed and enhanced by mi R-192-5 p mimic and inhibitor, respectively, in wild-type SCD-1(P < 0.01) but not in mutant SCD-1. Mi R-192-5 p overexpression reduced lipid accumulation significantly in PA-treated Huh7 cells, and SCD-1 si RNA transfection abrogated the lipid deposition aggravated by mi R-192-5 p inhibitor(P < 0.01).CONCLUSION This study demonstrates that mi R-192-5 p has a negative regulatory role in lipid synthesis, which is mediated through its direct regulation of SCD-1.

Tissue-engineered rhesus monkey nerve grafts for the repair of long ulnar nerve defects:similar outcomes to autologous nerve grafts

Acellular nerve allografts can help preserve normal nerve structure and extracellular matrix composition. These allografts have low immunogenicity and are more readily available than autologous nerves for the repair of long-segment peripheral nerve defects. In this study, we repaired a 40-mm ulnar nerve defect in rhesus monkeys with tissue-engineered peripheral nerve, and compared the outcome with that of autograft. The graft was prepared using a chemical extract from adult rhesus monkeys and seeded with allogeneic Schwann cells. Pathomo- rphology, electromyogram and immunohistochemistry findings revealed the absence of palmar erosion or ulcers, and that the morphology and elasticity of the hypothenar eminence were normal 5 months postoperatively. There were no significant differences in the mean peak compound muscle action potential, the mean nerve conduction velocity, or the number of neurofilaments between the experimental and control groups. However, outcome was significantly better in the experimental group than in the blank group. These findings suggest that chemically extracted allogeneic nerve seeded with autologous Schwann cells can repair 40-mm ulnar nerve defects in the rhesus monkey. The outcomes are similar to those obtained with autologous nerve graft.

Comparison between direct repair and humana cellular nerve allografting during contralateral C7 transfer to the upper trunk for restoration of shoulder abduction and elbow flexion

Direct coaptation of contralateral C7 to the upper trunk could avoid the interposition of nerve grafts. We have successfully shortened the gap and graft lengths, and even achieved direct coaptation. However, direct repair can only be performed in some selected cases, and partial procedures still require autografts, which are the gold standard for repairing neurologic defects. As symptoms often occur after autografting, human acellular nerve allografts have been used to avoid concomitant symptoms. This study investigated the quality of shoulder abduction and elbow flexion following direct repair and acellular allografting to evaluate issues requiring attention for brachial plexus injury repair. Fifty-one brachial plexus injury patients in the surgical database were eligible for this retrospective study. Patients were divided into two groups according to different surgical methods. Direct repair was performed in 27 patients, while acellular nerve allografts were used to bridge the gap between the contralateral C7 nerve root and upper trunk in 24 patients. The length of the harvested contralateral C7 nerve root was measured intraoperatively. Deltoid and biceps muscle strength, and degrees of shoulder abduction and elbow flexion were examined according to the British Medical Research Council scoring system;meaningful recovery was defined as M3–M5. Lengths of anterior and posterior divisions of the contralateral C7 in the direct repair group were 7.64 ± 0.69 mm and 7.55 ± 0.69 mm, respectively, and in the acellular nerve allografts group were 6.46 ± 0.58 mm and 6.43 ± 0.59 mm, respectively. After a minimum of 4-year follow-up, meaningful recoveries of deltoid and biceps muscles in the direct repair group were 88.89% and 85.19%, respectively, while they were 70.83% and 66.67% in the acellular nerve allografts group. Time to C5/C6 reinnervation was shorter in the direct repair group compared with the acellular nerve allografts group. Direct repair facilitated the restoration of shoulder abduction and elbow flexion. Thus, if direct coaptation is not possible, use of acellular nerve allografts is a suitable option. This study was approved by the Medical Ethical Committee of the First Affiliated Hospital of Sun Yat-sen University, China (Application ID:[2017] 290) on November 14, 2017.

Three-dimensional visualization of the functional fascicular groups of a long-segment peripheral nerve

The three-dimensional（3D） visualization of the functional bundles in the peripheral nerve provides direct and detailed intraneural spatial information. It is useful for selecting suitable surgical methods to repair nerve defects and in optimizing the construction of tissue-engineered nerve grafts. However, there remain major technical hurdles in obtaining, registering and interpreting 2D images, as well as in establishing 3D models. Moreover, the 3D models are plagued by poor accuracy and lack of detail and cannot completely reflect the stereoscopic microstructure inside the nerve. To explore and help resolve these key technical problems of 3D reconstruction, in the present study, we designed a novel method based on re-imaging techniques and computer image layer processing technology. A 20-cm ulnar nerve segment from the upper arm of a fresh adult cadaver was used for acetylcholinesterase（ACh E） staining. Then, 2D panoramic images were obtained before and after ACh E staining under the stereomicroscope. Using layer processing techniques in Photoshop, a space transformation method was used to fulfill automatic registration. The contours were outlined, and the 3D rendering of functional fascicular groups in the long-segment ulnar nerve was performed with Amira 4.1 software. The re-imaging technique based on layer processing in Photoshop produced an image that was detailed and accurate. The merging of images was accurate, and the whole procedure was simple and fast. The least square support vector machine was accurate, with an error rate of only 8.25%. The 3D reconstruction directly revealed changes in the fusion of different nerve functional fascicular groups. In conclusion. The technique is fast with satisfactory visual reconstruction.

Clinical characteristics and treatment of severe encephalitis associated with neurogenic pulmonary edema caused by enterovirus 71 in China

BACKGROUND： Hand-foot-mouth disease has become a major public health issue in children in China. In the present prospective study we investigated the clinical characteristics and emergency management of children with severe encephalitis associated with NPE caused by enterovirus 71.METHODS： The study was conducted in 2 pediatric intensive care units （PICUs） over a 2-month period. Clinical records were reviewed of critically ill children with severe encephalitis associated with NPE caused by EV71 who were admitted to PICUs during the period of May to June 2008 in Fuyang.RESULTS： We reviewed the complete records of 36 children, of whom 23 （63.9%） were male and 13 （36.1%） female. Their age ranged from 4 to 48 months, with an average of 15.8 months. All children except one were under 3 years of age. The overall mortality in these children was 19.4%. The average duration of critical life threatening signs and symptoms was 2.1 days （12 hours-5 days）. Nervous system diseases included brainstem encephalitis in 27 children （75%）, brainstem encephalitis associated with myelitis in 6 children （16.7%）, and general encephalitis in 3 chidren （8.3%）, respectively. In 12 patients of NPE （33.3%） pink or bloody bubble sputum and asymmetric pulmonary edema or hemorrhage was the primary manifestation but no typical exanthema was observed. Five children died of acute onset of NPE and / or pulmonary hemorrhage with rapid progression of cardiopulmonary failure within hours after admission. Therapeutic management consisted of mechanical ventilation and administration of mannitol, methylprednisolone, intravenous immunoglobulin （IVIG） and vasoactive drugs, associated with the need of fluid volume resuscitation in 9 （25%） of the 36 children.CONCLUSION： In children less than 3 years of age found to be affected by severe EV71 encephalitis associated with NPE, one fifth may die. The major organ systems infected by severe EV71 include the central nervous system, the respiratory system, and the cardiovascular system. Early diagnosis and evaluation, respiratory support, treatment of intracranial hypertension, and mainttenance of function of the cardiovascular system are the most important therapeutic measures.

A rapid micro-magnetic resonance imaging scanning for three-dimensional reconstruction of peripheral nerve fascicles

The most common methods for three-dimensional reconstruction of peripheral nerve fascicles include histological and radiology techniques. Histological techniques have many drawbacks including an enormous manual workload and poor image registration. Micro-magnetic resonance imaging（Micro-MRI）, an emerging radiology technique, has been used to report results in the brain, liver and tumor tissues. However, micro-MRI usage for obtaining intraneural structures has not been reported. The aim of this study was to present a new imaging method for three-dimensional reconstruction of peripheral nerve fascicles by ~1T micro-MRI. Freshly harvested sciatic nerve samples from an amputated limb were divided into four groups. Two different scanning conditions（Mannerist Solution/GD-DTPA contrast agent, distilled water） were selected, and both T1 and T2 phases programmed for each scanning condition. Three clinical surgeons evaluated the quality of the images via a standardized scale. Moreover, to analyze deformation of the two-dimensional image, the nerve diameter and total area of the micro-MRI images were compared after hematoxylin-eosin staining. The results show that rapid micro-MRI imaging method can be used for three-dimensional reconstruction of the fascicle structure. Nerve sample immersed in contrast agent（Mannerist Solution/GD-DTPA） and scanned in the T1 phase was the best. Moreover, the nerve sample was scanned freshly and can be recycled for other procedures. MRI images show better stability and smaller deformation compared with histological images. In conclusion, micro-MRI provides a feasible and rapid method for three-dimensional reconstruction of peripheral nerve fascicles, which can clearly show the internal structure of the peripheral nerve.

Various changes in cryopreserved acellular nerve allografts at-80°C

The experimental design evaluated histological,mechanical,and biological properties of allogeneic decellularized nerves after cryopreservation in a multi-angle,multi-directional manner to provide evidence for long-term preservation.Acellular nerve allografts from human and rats were cryopreserved in a cryoprotectant（10% fetal bovine serum,10% dimethyl sulfoxide,and 5% sucrose in RPMI1640 medium） at-80°C for 1 year,followed by thawing at 40°C or 37°C for 8 minutes.The breaking force of acellular nerve allografts was measured using a tensile test.Cell survival was determined using L-929 cell suspensions.Acellular nerve allografts were transplanted into a rat model with loss of a 15-mm segment of the left sciatic nerve.Immunohistochemistry staining was used to measure neurofilament 200 expression.Hematoxylin-eosin staining was utilized to detect relative muscle area in gastrocnemius muscle.Electron microscopy was applied to observe changes in allograft ultrastructure.There was no obvious change in morphological appearance or ultrastructure,breaking force,or cytotoxicity of human acellular nerve allografts after cryopreservation at-80°C.Moreover,there was no remarkable change in neurofilament 200 expression,myelin sheath thickness,or muscle atrophy when fresh or cryopreserved rat acellular nerve allografts were applied to repair nerve injury in rats.These results suggest that cryopreservation can greatly extend the storage duration of acellular nerve tissue allografts without concomitant alteration of the physiochemical and biological properties of the engineered tissue to be used for transplantation.

复合式缓冲液压缸在电液负载模拟器中的应用

为解决飞机舵机电液负载模拟器在不同梯度加载实验中,由于舵机主动运动导致液压缸两腔产生强迫流量,进而产生多余力干扰的问题,提出基于复合式缓冲液压缸的系统结构设计。根据系统工作原理及液压缓冲结构特点,设计该液压缸的结构形式并建立其数学模型。采用AMESim仿真软件建立执行机构的仿真模型,并进行系统动态特性仿真实验。研究结果表明,该液压缸系统能够减小活塞运行过程中产生的机械碰撞,缓解液压缸两腔的强迫流量压力,抑制并消除多余力干扰,进而提高电液负载模拟器的负载性能,具有较高的工程实践价值。

Cartilage oligomeric matrix protein enhances the vascularization of acellular nerves

Vascularization of acellular nerves has been shown to contribute to nerve bridging.In this study,we used a 10-mm sciatic nerve defect model in rats to determine whether cartilage oligomeric matrix protein enhances the vascularization of injured acellular nerves.The rat nerve defects were treated with acellular nerve grafting（control group） alone or acellular nerve grafting combined with intraperitoneal injection of cartilage oligomeric matrix protein（experimental group）.As shown through two-dimensional imaging,the vessels began to invade into the acellular nerve graft from both anastomotic ends at day 7 post-operation,and gradually covered the entire graft at day 21.The vascular density,vascular area,and the velocity of revascularization in the experimental group were all higher than those in the control group.These results indicate that cartilage oligomeric matrix protein enhances the vascularization of acellular nerves.

Mechanisms governing the evolution of a long-lived northwest vortex that caused a series of disasters in Northwest China

The northwest vortex(NWV)is a type of mesoscale vortex that appears with a relatively high frequency in Northwest China.To further the understanding of the NWV’s evolution,in this study,the moisture and circulation budgets of a long-lived NWV(~132 h)that appeared in early August 2019 were calculated.This vortex induced a series of torrential rainfall events in Northwest China and Mongolia,which caused severe transmission line faults and urban waterlogging.Synoptic analyses indicate that the NWV was generated in a favorable background environment characterized by notable upper-level divergence and strong mid-level warm advection.The moisture budget shows that the East China Sea and Bohai Sea acted as the main moisture sources for the NWV-associated precipitation,and the water vapor was transported into the rainfall regions mainly by easterly and southeasterly winds.The circulation budget indicates that,during the developing stage,convergence-related vertical stretching was a dominant factor for the NWV’s development;whereas,the vortex’s displacement from regions with stronger cyclonic vorticity to those with weaker cyclonic vorticity mainly decelerated its development.In the decaying stage,divergence-related vertical shrinking and the net export of cyclonic vorticity due to the eddy flow’s transport resulted in the NWV’s dissipation.

六价铬对大鼠学习记忆的影响

目的观察六价铬[Cr(VI)]对大鼠学习记忆的影响。方法母鼠哺乳期分别给予双蒸水(对照组)、低(0.8 mg/kg)、中(4.0 mg/kg)、高(20 mg/kg)重铬酸钾溶液(低、中、高剂量重铬酸钾组)。断乳后仔鼠灌胃与其母鼠相同剂量的重铬酸钾溶液,共6个月。石墨炉原子吸收光谱法测定大鼠脑组织中铬含量;Morris水迷宫实验测试大鼠学习记忆能力;尼氏染色和免疫组织化学等方法观察大鼠海马神经细胞及星形胶质细胞的形态学改变;高效液相色谱法测定谷胱甘肽(GSH)含量。结果低、中、高剂量重铬酸钾组脑组织中铬含量与对照组比较,差异有统计学意义(P<0.05)。随着染毒剂量增加,大鼠平均逃避潜伏期和第1次寻找平台的潜伏期延长,穿越原平台次数减少,在原平台象限停留时间缩短(P<0.05)。与对照组比较,重铬酸钾组大鼠海马组织出现损伤、神经元排列紊乱及细胞核浓染固缩。星形胶质细胞GFAP阳性表达现象随剂量的增加而加重。与对照组比较,铬暴露组大鼠海马组织的GSH含量下降(P<0.05)。结论重铬酸钾可引起大鼠海马神经元结构及其功能损伤,学习记忆能力降低,其机制可能与Cr(VI)所诱导的氧化应激有关。

Experimental study on hypersonic crossflow instability over a swept flat plate by flow visualization

An experimental study on the traveling crossflow instability over a 60∘swept flat plate was conducted.The Mach number is 6,the angle of attack of the model is 5∘.The traveling crossflow waves and the secondary instability of the traveling crossflow waves were visualized by nano-tracer-based planar laser scattering(NPLS)technique.In the spanwise NPLS images,the traveling crossflow waves appeared as regular strikes,and the secondary instability appeared as small eddies attached to strikes.The wavelet transform was used to study the wavelength contents of the traveling crossflow waves.The most amplified wavelength is stable before the secondary instability happening,which is around 12 mm at Re_(∞)=3.45×10^(6)m^(−1).Besides,the Reynolds number effects on the boundary layer transition and traveling crossflow instability were discussed.

Current status and challenge in clinical work of autism spectrum disorders in China

Autism spectrum disorders (ASDs) are a group of neurodevelopmentaldisorders featured by social communicationand interaction deficits, and with limited interests andrepetitive behaviors. In China, ASDs was first reported byTao from Nanjing Brain Hospital in the early 1980s [ 1 , 2 ].Since then, more children with autism have been diagnosed.While the past more than 30 years have witnessed steadygrowth in ASD research and clinical diagnosis and interventionin China, there are still many challenges to overcome.In this article, we will present the current status of prevalence,screening and diagnosis of ASD in China and proposefurther eff orts for practitioners and policy-makers to secureoptimal outcomes for children with ASD.

The Local Bifurcation and Stability of Nontrivial Steady States of a Logistic Type of Chemotaxis

Chemotaxis is a type of oriented movement of cells in response to the concentration gradient of chemical substances in their environment. We consider local existence and stability of nontrivial steady states of a logistic type of chemotaxis. We carry out the bifurcation theory to obtain the local existence of the steady state and apply the expansion method on the chemotaxis to investigate the bifurcation direction. Moreover, by applying the bifurcation direction, we obtain the bifurcating steady state is stable when the bifurcation curve turns to right under certain conditions.