B元素添加对超声辅助铸造法制备B_(4)C_(p)/Al复合材料显微组织和力学性能的影响

通过在Al-B_4C-K_2TiF_6反应体系中添加KBF_4引入B元素,采用超声辅助铸造法制备B_(4)C_(p)/Al复合材料。研究B元素添加对复合材料显微组织、力学性能及界面反应机理的影响。实验结果表明,添加B元素可以改变B_(4)C_(p)/Al的界面结构,使更多的小粒径TiB_2颗粒分布在基体中,因此空化和声流效应进一步增强,熔体中的B_4C团簇被破碎,使复合材料组织更加均匀、综合力学性能得到改善。

Combined hepatic segment color rendering technique improves the outcome of anatomical hepatectomy in patients with hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is the third most common cause for cancer-related death worldwide,especially in China[1].Hepatectomy is considered one of the most potentially curative therapies for HCC[2].As HCC is capable of vascular invasion and metastasis via the portal venous system,anatomical resection is often performed to reduce tumor recurrence.This process involves resecting the tumor-bearing portal branches and the corresponding hepatic parenchyma[3].Certain comparative studies have demonstrated better overall survival and disease-free survival with the use of anatomical resection when compared with nonanatomical resection[4–6].

Usefulness of three-dimensional visualization technology in minimally invasive treatment for infected necrotizing pancreatitis

AIM To explore the value of three-dimensional(3 D) visualization technology in the minimally invasive treatment for infected necrotizing pancreatitis(INP). METHODS Clinical data of 18 patients with INP, who were admitted to the PLA General Hospital in 2017, were retrospectively analyzed. Two-dimensional images of computed tomography were converted into 3 D images based on 3 D visualization technology. The size, number, shape and position of lesions and their relationship with major abdominal vasculature were well displayed. Also, percutaneous catheter drainage(PCD) number and puncture paths were designed through virtual surgery(percutaneous nephroscopic necrosectomy) based on the principle of maximum removal of infected necrosis conveniently.RESULTS Abdominal 3 D visualization images of all the patients were well reconstructed, and the optimal PCD puncture paths were well designed. Infected necrosis was conveniently removed in abundance using a nephroscope during the following surgery, and the median operation time was 102(102 ± 20.7) min. Only 1 patient underwent endoscopic necrosectomy because of residual necrosis. CONCLUSION The 3 D visualization technology could optimize the PCD puncture paths, improving the drainage effect in patients with INP. Moreover, it significantly increased the efficiency of necrosectomy through the rigid nephroscope. As a result, it decreased operation times and improved the prognosis.

Integrative transcriptome,proteome,and microRNA analysis reveals the effects of nitrogen sufficiency and deficiency conditions on theanine metabolism in the tea plant(Camellia sinensis)

Nitrogen(N)is associated with amino acid metabolism in higher plants.Theanine is an important amino acid in tea plants.To explore the relationship between theanine metabolism and N conditions,we examined the differentially expressed genes(DEGs),proteins(DEPs),and microRNAs(DEMs)involved in theanine metabolism in tea plant shoots and roots under N sufficiency and deficiency conditions.Transcriptome,proteome,and microRNA analyses were performed on tea plant shoots and roots under N sufficiency and deficiency conditions.The contents of theanine,expression levels of genes involved in theanine metabolism,contents of proteinogenic amino acids,and activity of enzymes were analyzed.The DEP–DEG correlation pairs and negative DEM–DEG interactions related to theanine metabolism were identified based on correlation analyses.The expression profiles of DEGs and negative DEM–DEG pairs related to theanine biosynthesis were consistent with the sequencing results.Our results suggest that the molecular and physiological mechanism of theanine accumulation is significantly affected by N sufficiency and deficiency conditions.The DEGs,DEPs,and DEMs and the activity of the enzymes involved in theanine biosynthesis might play vital roles in theanine accumulation under N sufficiency and deficiency conditions in the shoots and roots of tea plants.

Differentially expressed protein and gene analysis revealed the effects of temperature on changes in ascorbic acid metabolism in harvested tea leaves

Tea is an important non-alcoholic beverage worldwide.Tea quality is determined by numerous secondary metabolites in harvested tea leaves,including tea polyphenols,theanine,caffeine,and ascorbic acid(AsA).AsA metabolism in harvested tea leaves is affected by storage and transportation temperature.However,the molecular mechanisms underlying AsA metabolism in harvested tea leaves exposed to different storage and transportation temperature conditions remain unclear.Here we performed RP-HPLC to detect dynamic changes in AsA content in tea leaves subjected to high-(38°C),low-(4°C),or room-temperature(25°C)treatments.The AsA distribution and levels in the treated tea leaves were analyzed using cytological–anatomical characterization methods.The differentially expressed CsAPX1 and CsDHAR2 proteins,which are involved in the AsA recycling pathway,were identified from the corresponding proteomic data using iTRAQ.We also analyzed the expression profiles of 18 genes involved in AsA metabolism,including CsAPX1 and CsDHAR2.AsA was mainly distributed in tea leaf mesophyll cells.High-and low-temperature treatments upregulated the CsAPX1 and CsDHAR2 proteins and induced CsAPX and CsDHAR2 gene expression.These results indicated that the CsAPX1 and CsDHAR2 proteins might have critical roles in AsA recycling in tea leaves.Our results provide a foundation for the in-depth investigation of AsA metabolism in tea leaves during storage and transportation,and they will promote better tea flavor in tea production.

Regulatory effects of hydrogen sulfide on alveolar epithelial cell endoplasmic reticulum stress in rats with acute lung injury

BACKGROUND: The present study was undertaken to examine the regulatory effect of hydrogen sulfide(H2S) on endoplasmic reticulum stress in alveolar epithelial cells of rats with acute lung injury(ALI) induced by oleic acid(OA).METHODS: Seventy-two male Sprague Dawley(SD) rats were divided into control group, oleic acid-induced ALI group(OA group), oleic acid-induced ALI with sodium hydrosulfide(Na HS) pretreatment group(OA+Na HS group), and sodium hydrosulfide treatment group(Na HS group). Rats of each group were further subdivided into 3 subgroups. Index of quantitative assessment of histological lung injury(IQA), wet/dry weight ratio(W/D) and H2 S level of lung tissues were measured. The expressions of endoplasmic reticulum stress markers including glucose-regulated protein 78(GRP78) and α-subunit of eukaryotic translation initiation factor-2(el F2α) in lung tissues were measured by immunohistochemical staining and Western blotting.RESULTS: The IQA score and W/D ratio of lung tissues at the three time points significantly increased in rats injected with OA, but significantly decreased in other rats injected with OA and Na HS. The level of H2 S in lung tissue at the three time points significantly decreased in rats injected with OA, but significantly increased in other rats injected with both OA and Na HS. GRP78 and el F2α decreased in rats injected with OA, but increased in other rats injected with both OA and Na HS, especially at 4-hour and 6-hour time points.CONCLUSION: The results suggested that H2 S could promote alveolar epithelial cell endoplasmic reticulum stress in rats with ALI.

胰腺干细胞和胰岛细胞在糖尿病大鼠治疗中的疗效观察

目的探讨大鼠胰腺干细胞与胰岛细胞移植在大鼠糖尿病治疗中的疗效。方法通过链脲菌素复制1型糖尿病大鼠模型并随机分为胰岛细胞组和胰腺干细胞组。用胶原酶V分别消化新生和成年大鼠胰腺,Percoll梯度离心分离胰岛细胞和胰腺干细胞。采用Bonner-Weir法诱导胰腺干细胞分化,DTZ染色检测移植物纯度,AO/PI检测移植物活性。分别记录手术前后大鼠血糖水平、胰岛素水平及移植物存活时间;高糖刺激实验和腹腔糖耐量评价移植物功能;取各组大鼠移植部位标本行HE染色和免疫组织化学染色,观察组织形态学变化。结果胰岛细胞组和胰腺干细胞组血糖分别在术后3和5 d恢复正常(P<0.05),两组大鼠术后不同时间点的血糖有差异(P<0.05),胰腺干细胞组的降糖能力强于胰岛细胞组(P<0.05)。两组大鼠移植后7 d血清胰岛素水平均较术前升高(P<0.05)。高糖刺激实验表明,各组移植后15和65 d高糖刺激后的C肽水平较刺激前升高(P<0.05),胰岛细胞组移植后65 d高糖刺激后C肽水平低于胰腺干细胞组(P<0.05),胰岛素和C肽水平监测结果表明胰腺干细胞组移植物胰岛素分泌维持时间长于胰岛细胞组。移植后腹腔糖耐量实验结果表明移植物均功能良好。胰岛细胞组和胰腺干细胞组移植物的中位存活时间分别为73和88 d,Kaplan-Meier曲线分析提示胰腺干细胞组移植物生存时间较胰岛细胞组延长(P<0.05)。HE染色提示肝脏门静脉移植区域可见新生血管包绕的胰岛细胞团,免疫组织化学染色证实细胞团胰岛素阳性。结论胰腺干细胞分化后经门静脉移植能安全有效地发挥降糖作用,疗效优于胰岛细胞移植。

Verapamil inhibits scar formation after peripheral nerve repair in vivo

The calcium channel blocker,verapamil,has been shown to reduce scar formation by inhibiting fibroblast adhesion and proliferation in vitro.It was not clear whether topical application of verapamil after surgical repair of the nerve in vivo could inhibit the formation of excessive scar tissue.In this study,the right sciatic nerve of adult Sprague-Dawley rats was transected and sutured with No.10-0 suture.The stoma was wrapped with gelfoam soaked with verapamil solution for 4 weeks.Compared with the control group（stoma wrapped with gelfoam soaked with physiological saline）,the verapamil application inhibited the secretion of extracellular matrix from fibroblasts in vivo,suppressed type I and III collagen secretion and increased the total number of axons and the number of myelinated axons.These findings suggest that verapamil could reduce the formation of scar tissue and promote axon growth after peripheral nerve repair.

Oxygen isotopic ratios toward molecular clouds in the Galactic disk

We present our observations of the J = 1-0 rotation transitions in molecular isotopes C^18O and C^17O toward a sample of molecular clouds with different galactocentric distances, using the Delingha 13.7 m（DLH 13.7 m） telescope, administered by Purple Mountain Observatory, and its 9-beam SIS receiver.Complementary observations toward several sources with large galactocentric distance are obtained with the IRAM 30 m and Mopra 22 m telescopes. C^18O/C^17O abundance ratios reflecting the ^（18）O/^（17）O isotope ratios are obtained from integrated intensity ratios of C^18O and C^17O. We derived the ratio value for 13 sources covering a galactocentric distance range of 3 kpc to 16 kpc. In combination with our mapping results that provide a ratio value of 3.01±0.14 in the Galactic center region, it shows that the abundance ratio tends to increase with galactocentric distance, i.e., it supports a radial gradient along the Galactic disk for the abundance ratio. This is consistent with the inside-out formation scenario of our Galaxy. However, our results may suffer from small samples with large galactocentric distance. Combining our data with multitransition lines of C^18O and C^17O will be helpful for constraining opacities and abundances and further confirming the Galactic radial gradient shown by the isotope ratio ^（18）O/^（17）O.

^(3)S_(1)–^(3)D_(1) coupled channel Λ_(c)N interactions:chiral effective field theory versus lattice QCD

We study the lattice QCDΛ_(c)N phase shifts for the^(3)S_(1)-^(3)D_(1)coupled channel using both the leading order covariant chiral effective theory and the next-to-leading order non-relativistic chiral effective field theory(ChEFT).We show that although it is possible to describe simultaneously the^(3)S_(1)and^(3)D_(1)phase shifts and the inelasticityη_(1),the fitted energy range is quite small,only up to E_(c.m.)=5 MeV.This raises concerns regarding the consistency between leading/next-to-leading order ChEFT and the lattice QCD simulations.

Strangeness S=-2 baryon-baryon interactions and femtoscopic correlation functions in covariant chiral effective field theory

We study the baryon-baryon interactions with strangeness S=-2 and corresponding momentum correlation functions in leading order covariant chiral effective field theory.The relevant low energy constants are determined by fitting to the latest HAL QCD simulations,taking into account all the coupled channels.Extrapolating the so-obtained strong interactions to the physical point and considering both quantum statistical effects and the Coulomb interaction,we calculate the ΛΛ and Ξ^(-)p correlation functions with a spherical Gaussian source and compare them with recent experimental data.We find a good agreement between our predictions and the experimental measurements by using the source radius determined in proton-proton correlations,which demonstrates the consistency between theory,experiment,and lattice QCD simulations.Moreover,we predict the Σ^(+)Σ^(+),Σ^(+)Λ,and Σ^(+)Σ^(-) interactions and corresponding momentum correlation functions.We further investigate the influence of the source shape and size of the hadron pair on the correlation functions studied and show that the current data are not very sensitive to the source shape.Future experimental measurements of the predicted momentum correlation functions will provide a non-trivial test of not only SU(3) flavor symmetry and its breaking but also the baryon-baryon interactions derived in covariant chiral effective field theory.

Risk factors for acute kidney injury in patients with acute myocardial infarction

Background:Acute kidney injury (AKI) is a serious and fatal complication of acute myocardial infarction (AMI).It has high shortand long-term mortality rates and a poor prognosis but is potentially preventable.However,the current incidence,risk factors,and outcomes of AKI in the Chinese population are not well understood and would serve the first step to identify high-risk patients who could receive preventative care.Methods:The medical data of 1124 hospitalized patients diagnosed with AMI from October 2013 to September 2015 were reviewed.AKI was defined according to the 2012 Kidney Disease Improving Global Outcomes criteria.All the patients were divided into either the AKI group or the non-AKI group.A univariate comparison analysis was performed to identify possible risk factors associated with AKI.A multiple logistic regression analysis was used to identify the independent risk factors for AKI in patients with AMI.Results:Overall,the incidence of AKI was 26.0%.The mortality rate of the AKI group was 20.5 %,and the mortality rate of the nonAKI group was 0.6%(P < 0.001).Logistic regression analysis showed that the independent risk factors for AKI in patients with AMI included:age (>60 years old)(odds ratio [OR] 1.04,95% confidence interval [CI] 1.02-1.05,P =0.000),hypertension (OR 2.51,95% CI 1.62-3.87,P =0.000),chronic kidney disease (OR 3.52,95% CI 2.01-6.16,P =0.000),Killip class ≥3 (OR 5.22,95% CI 3.07-8.87,P =0.000),extensive anterior myocardial infarction (OR 3.02,95% CI 1.85--4.93,P =0.000),use of furosemide (OR 1.02,95% CI 1.02-1.03,P =0.000),non-use of angiotensin-converting enzyme inhibitors/angiotensin receptor blocker (OR 1.58,95% CI 1.04-2.40,P =0.032).These factors provided an accurate tool to identify patients at high risk of developing AKI.Contusions:Approximately 26.0% of patients undergoing AMI developed AKI,and the development of AKI was strongly correlated with in-hospital mortality.The risk factors for AKI in patients with AMI were determined to help identify high-risk patients and make appropriate clinical decisions.

Room-temperature phosphorescence from purely organic materials

Room-temperature phosphorescence（RTP） materials have attracted great attention due to their involvement of excited triplet states and comparatively long decay lifetimes.In this short review,recent progress on enhancement of RTP from purely organic materials is summarized.According to the mechanism of phosphorescence emission,two principles are discussed to construct efficient RTP materials：one is promoting intersystem crossing（ISC） efficiency by using aromatic carbonyl,heavyatom,or/and heterocycle/heteroatom containing compounds;the other is suppressing intramolecular motion and intermolecular collision which can quench excited triplet states,including embedding phosphors into polymers and packing them tightly in crystals.With aforementioned strategies,RTP from purely organic materials was achieved both in fluid and rigid media.

Thermal Properties of Mg–Al/AlN Composites Fabricated by Powder Metallurgy

Magnesium matrix composites reinforced with AlN particles were fabricated by the powder metallurgy technique.Different mixing methods were used in this study to control the distribution of Al N particles.The microstructure,thermal diffusivity and thermal expansion of the Mg–Al/Al N composites using different mixing methods were investigated.The results showed that the intergranular and intragranular distributions of Al N particles were obtained,respectively,by controlling the mixing methods.The composite with intragranular particles exhibited lower thermal diffusivity because of the existences of more interfaces,defects and grain boundaries,which acted as scattering centers and reduced the mean free path of electrons and phonons.The existence of Al N particles lowered the coefficient of thermal expansion（CTE）and enhanced the dimensional stability of the composites.And the use of the improved mixing method further reduced the CTE of Mg–Al/Al N composites.

Altered Matrix Metalloproteinases Expression in Placenta from Patients with Gestational Diabetes Mellitus

To the Editor：Gestational diabetes mellitus （GDM） is defined as glucose intolerance with the onset of pregnancy and is related to increased maternal and fetal risks.Incidence of GDM varies in different countries and the prevalence ranges between 4% and 17%. GDM is one of the most common medical complications of pregnancy,negatively affecting fetal development and metabolic balance.If untreated,GDM can cause fetal malformation,macrosomia,fetal growth retardation,and even intrauterine fetal death.Recent studies have shown correlations between GDM and postpartum insulin resistance,pregnancy-induced hypertension,and dyslipidemia.GDM has also been shown to be associated with placental abnormalities including altered placental function,oxidative stress,and vascular dysfunction.

Blood compatibility of zinc-calcium phosphate conversion coating on Mg-1.33Li-O.6Ca alloy

Magnesium alloys as a new class of biomaterials possess biodegradability and biocompatibility in comparison with currently used metal implants. However, their rapid corrosion rates are necessary to be manipulated by appropriate coatings. In this paper, a new attempt was used to develop a zinc-calcium phosphate （Zn-Ca-P） conversion coating on Mg-1.33Li-0.6Ca alloys to increase the biocompatibility and improve the corrosion resistance. In vitro blood biocompatibility of the alloy with and without the Zn-Ca-P coating was investigated to determine its suitability as a degradable medical biomaterial. Blood biocompatibility was assessed from the hemolysis test, the dynamic cruor time test, blood cell count and SEM observation of the platelet adhesion to membrane surface. The results showed that the Zn-Ca-P coating on Mg-1.33Li-0.6Ca alloys had good blood compatibility, which is in accordance with the requirements for medical biomaterials.

Left hepatectomy with caudate lobe resection using the methylene blue staining technique for bismuth lllb hilar cholangiocarcinoma

Left hepatectomy with caudate lobe resection has been widely accepted as the standard treatment for bismuth IIIb hilar cholangiocarcinoma(1-6).However,there is no clear boundary between the right caudate lobe and the right posterior section.The methylene blue staining technique are commonly used to delineate the margin of the relevant hepatic segment for anatomic hepatectomy(7).Herein,we described this technique to demarcate the boundary between the caudate lobe and the right posterior lobe for an en bloc resection of the tumor and improve the R0 surgical margin.

Characteristics of Adult Fractures in Emergency Department in Beijing Jishuitan Hospital during 2009-2016

Fracture was a common injury in adults.Moreover,the number of fractures showed an increasing trend in previous studies.Fractures bring suffering and enormous financial burdens to patients and their families. As the development of urbanization,the incidence of fractures increases gradually.However,the research on the spectrum of adult fractures has not been enough in Beijing.As a trauma emergency center of Beijing,Jishuitan Hospital is a center for adults＇ first aid and treatment of fractures,we designed this study to provide a reliable basis for better adjustment of adult fractures treatment and prevention.