A Dodecahedrane-like Molecule C_(12)H_(12)B_8 with Uncommon T_h Symmetry

The molecule with Th symmetry is rare.A dodecahedrane-like molecule C12H12B8 with uncommon Th symmetry has been reported here.Density functional calculations and minimization techniques have been employed to characterize its structural and electronic properties.Its geometry,electronic properties,vibrational frequencies and heat of formation have been calculated at the B3LYP/6-311＋G（d,p） level of theory.The absence of imaginary vibrational frequency confirms that it corresponds to true minimum on the potential energy hypersurface.Its vibrational bands in the IR intensity have been discussed and compared with future experimental identification.At the B3LYP/6-311＋G（d,p） level,the heat of formation has been calculated to be 720.9 kJ mol^-1 using the isodesmic reaction.According to this value,it is a potential high energy density molecule.

Spatial Availability of Nitrogen and Pesticides in the Surface Layers of Agricultural Soils of Tropical Hydrosystems in the Wet Season: Case of the BéréWatershed in Côte d’Ivoire (West Africa)

The objective of this study was to assess the contribution of the spatial organization of cropping systems and the physicochemical properties of surface layers of the agricultural zones soils in tropical hydrosystems to the spatial availability of nitrogen and pesticides during the wet season, such as the Béré watershed (BW) in C?te d’Ivoire. For this purpose, after mapping the spatial distribution of the BW cropping systems based on the likelihood classification methodology of satellite images of the study area, 27 samples from the 0 - 20 cm horizon of the soil surface layers of the agricultural areas were taken during the wet and agricultural season of the year 2016. The Kjeldahl method has been used to evaluate the total nitrogen concentration and high-performance liquid chromatography (HPLC) chain made it possible for the analysis of pesticide residues in the soil solutions. Geostatistical analysis and processing of spatial data and physicochemical and agrochemical soil parameters revealed that two major agricultural areas stand out in the BW, namely the Béré upstream watershed (BUW) dominated at 32.65% by annual croppings (maize, cotton, rainfed or lowland rice, market gardening, etc.) and the Béré downstream watershed (BDW) by large areas of perennial croppings (cashew nuts, cocoa, etc.), i.e. 21.47%. Agricultural soils in BW are usually of the moderately desaturated ferralitic type with a low acid pH and a quite strong temperature, such as those of tropical soils’ characteristics. However, agricultural soils in the BUW are characterized by higher proportions of sand and coarse sand. The parameters such as total porosity, cation exchange capacity, clay, organic matter, silt, fine silt, coarse silt, and potassium ions, are higher in the soils of the agricultural area of the BDW. Moreover, soils in the agricultural areas of the BUW are less rich in total nitrogen (0.84 g·kg-1) in contrast to those of the BDW (1.2 g·kg-1). On the other hand, the median concentrations of total pesticides remain very high in the BUW (193.80 μg·kg-1) in front of those of the BDW (94.81 μg·kg-1). In addition, the biological family of herbicides was the most notable in BW. The chemical families of triazines (100% detection;79.37 μg·kg-1) are the most important in the agricultural area of the BUW with the very significant presence of active molecules of pesticides such as simazine (92.86% detection;13.17 μg·kg-1). However, in the BDW, urea substitute (100% detection;44.02 μg·kg-1) dominate, including the active substance chlortoluron (84.62% detection;10.12 μg·kg-1). The presence and abundance of nitrogen and pesticides in the soils of the agricultural areas of BW are strongly linked to the intensive use of these agrochemicals in cropping systems in recent decades in West African countries, even though most of the active molecules found are forbidden in several countries, especially in European countries. These are applied to tropical agricultural soils with physicochemical characteristics favorable to their retention in wet weather, as confirmed by the case of BW’s agricultural soils. Therefore, the BW’s water resources present worrying risks of contamination during rainy events that deserve to be assessed and monitored. Hence the need to take mitigating measures to this effect in order to preserve the quality of the environment.

七叶总皂苷及其中A B C D组分的抗炎作用实验研究

目的:药理研究和临床应用均证明,七叶总皂苷具有消炎的作用。目前对从七叶总皂苷中提取分离得到的A、B、C、D4种单组分的药理研究和临床应用尚未见报道。实验旨在研究A、B、C、D组分的药理作用并初步探讨其作用机制。通过与七叶总皂苷进行比较,从中筛选出疗效优于总皂苷和(或)毒副作用低于总皂苷的单组分,为进一步开发成新药提供前期的理论依据。

Heterofullerenes C_(48)N_(12) and C_(48)B_(12) with Rare T_h Symmetry: a DFT Study

The molecule with Th symmetry is rare. Two C60-1ike molecules C48N12 and C48B12 with rare Th symmetry have been reported here, which is an approach to seek for the molecule with rare Th symmetry. Their structural, electronic, vibrational, NMR, and thermodynamic properties have been calculated at the B3LYP/6-31G（d） level of theory. Vibrational modes have been assigned according to their symmetry. They all have 73 independent vibrational modes： 22 IR-active modes with Tu symmetry and 37 Raman-active modes with Ag, Eg and Tg symmetry, respectively. The heats of formation have been calculated using isodesmic reactions, and the values of C48N12 and C48B12 are 3812.0 and 3423.8 kJ mo1-1, respectively. According to the estimated band gaps for their fcc solid, they are all semiconducting materials, like C60, especially C48B12-based fcc solid.

Micronutrient deficiencies in patients with chronic atrophic autoimmune gastritis: A review

Chronic atrophic autoimmune gastritis (CAAG) is an organ-specific autoimmune disease characterized by an immune response, which is directed towards the parietal cells and intrinsic factor of the gastric body and fundus and leads to hypochlorhydria, hypergastrinemia and inadequate production of the intrinsic factor. As a result, the stomach’s secretion of essential substances, such as hydrochloric acid and intrinsic factor, is reduced, leading to digestive impairments. The most common is vitamin B12 deficiency, which results in a megaloblastic anemia and iron malabsorption, leading to iron deficiency anemia. However, in the last years the deficiency of several other vitamins and micronutrients, such as vitamin C, vitamin D, folic acid and calcium, has been increasingly described in patients with CAAG. In addition the occurrence of multiple vitamin deficiencies may lead to severe hematological, neurological and skeletal manifestations in CAAG patients and highlights the importance of an integrated evaluation of these patients. Nevertheless, the nutritional deficiencies in CAAG are largely understudied. We have investigated the frequency and associated features of nutritional deficiencies in CAAG in order to focus on any deficit that may be clinically significant, but relatively easy to correct. This descriptive review updates and summarizes the literature on different nutrient deficiencies in CAAG in order to optimize the treatment and the follow-up of patients affected with CAAG.

New Coumarins From Peacedanum Decursivum

Four new Coumarins named Decursitin B, C, D. F have been isolated from traditional Chinese medicine - the root of Peacedanum decursivum. Their structures were elucidated by chemical evidences and spectral analysis.

New Minor Cyclic Peptides from Brachystemma calycinum

From the ethanol extract of the roots of Brachystemma calycinum D. Don, a Chinese folk herb, four new minor cyclic peptides namely brachystemin A, B, C and D (1 - 4) have been isolated. Their structures were established as cyclo (Pro(1)-Phe-Leu-Ala(1)-Thr-Pro(2)-Ala(2)-Gly) (1), cyclo (Pro(1)-Ala-Phe-Trp-Asp-Pro(2)-Leu-Gly) (2), cyclo (Pro(1)-Ile-Gly-Pro(2)-Val-Ala(1)-Ala(2)-Tyr) (3) and cyclo ( Pro-OMet-Trp-Ile-Gly-Ala-Leu-Asp) (4) respectively by means of extensive spectral methods.

Theoretical Studies on the Coplanar Dicage Pentaprismane C_(16)H_(12)

A coplanar dicage pentaprismane molecule C16H12 has been studied by using DFT at B3LYP/D95* level and ab initio method at MP2/D95* level, and the vibrational frequencies of the molecule have been calculated at B3LYP/D95* level too. The results show that the molecule is thermodynamically stable. Some physico-chemical properties, such as geometry, simulated IR spectrum and heat of formation, have been reported.

Impact of comorbidities on the severity of chronic hepatitis B at presentation

AIM:To evaluate the clinical relevance of each cofactor on clinical presentation of chronic hepatitis B.METHODS:Out of 1366 hepatitis B surface antigen(HBsAg) positive subjects consecutively observed in 79 Italian hospitals,53(4.3%) showed as the only cofactor hepatitis D virus(HDV) infection [hepatitis B virus(HBV)/HDV group],130(9.5%) hepatitis C virus(HCV)(group HBV/HCV),6(0.4%) human immunodeficiencyvirus(HIV)(group HBV/HIV),138(10.2%) alcohol abuse(group HBV/alcohol);109(8.0%) subjects had at least two cofactors and 924 were in the cofactor-free(CF) group.RESULTS:Compared with patients in group CF those in group HBV/alcohol were older and more frequently had cirrhosis(P < 0.001),those in group HBV/HDV were younger(P < 0.001),more frequently resided in the south of the country and had cirrhosis(P <0.001),those in group HBV/HCV were older(P < 0.001) and more frequently had cirrhosis(P < 0.001).These cofactors were all independent predictors of liver cirrhosis in HBsAg positive patients.Multivariate analysis showed that an older age [odds ratio(OR) 1.06,95% CI:1.05-1.08],alcohol abuse with more than 8 drinks daily(OR 2.89,95% CI:1.81-4.62) and anti-HDV positivity(OR 3.48,95% CI:2.16-5.58) are all independently associated with liver cirrhosis.This association was found also for anti-HCV positivity in univariate analysis,but it was no longer associated(OR 1.23,95% CI:0.84-1.80) at multivariate analysis.CONCLUSION:Older age,HDV infection and alcohol abuse are the major determinants of severe liver disease in chronic HBV infection,while HCV replication plays a lesser role in the severity of hepatic damage.

HBsAg stimulates NKG2D receptor expression on natural killer cellsand inhibits hepatitis C virus replication

Background： Higher hepatitis B surface antigen （HBsAg） facilitates hepatitis C virus （HCV） clearance inpatients with hepatitis B virus （HBV）/HCV co-infection. We investigated the effect of exogenous HBsAgon the inhibition of HCV replication mediated by natural killer （NK） cells.

Theoretical basis of a beneficial role for vitamin D in viral hepatitis

Abnormal bone metabolism and dysfunction of the calcium-parathyroid hormone-vitamin D axis have been reported in patients with viral hepatitis. Some studies suggested a relationship between vitamin D and viral hepatitis. Genetic studies have provided an opportunity to identify the proteins that link vitamin D to the pathology of viral hepatitis (i.e., the major histocompatibility complex class Ⅱ molecules, the vitamin D receptor, cytochrome P 450 , the renin-angiotensin system, apolipoprotein E, liver X receptor, toll-like receptor, and the proteins regulated by the Sp1 promoter gene). Vitamin D also exerts its effects on viral hepatitis via non-genomic factors, i.e., matrix metalloproteinase, endothelial vascular growth factor, prostaglandins, cyclooxygenase-2, and oxidative stress. In conclusion, vitamin D could have a beneficial role in viral hepatitis. Calcitriol is best used for viral hepatitis because it is the active form of the vitamin D 3 metabolite.

北京C B D核心区概念性规划设计及Z3、Z4、Z5、Z6地块单体设计

根据北京CBD地区整体规划,北京商务中心区(CBD)核心区位于北京市朝阳区东三环北京商务中心区,西邻东三环,东至针织路,北依光华路,南至建国路,规划建设用地面积约12.7hm^2,建设规模约186万m^2(图1、2)。核心区内一共规划建设16栋超高层建筑。受业主委托,我们对CBD核心区进行整体规划设计,同时对其中的Z3、Z4、Z5、Z6地块的超高层进行单体的建筑设计(图3、10、11)。

DFT Studies on Thermal Stabilities,Electronic Structures,and ^(13)C Chemical Shifts of C_(24)O_2 Based on Fullerene C_(24)(D_6)

Quantum chemical calculations on some possible equilibrium geometries of C24O2 isomers derived from C24 （D6） and C24O have been performed using density functional theory （DFT） method. The geometric and electronic structures as well as the relative energies and thermal stabilities of various C24O2 isomers at the ground state have been calculated at the B3LYP/6-31G（d） level of theory. And the 1,4,2,5-C24O2 isomer was found to be the most stable geometry where two oxygen atoms were added to the longest carbon-carbon bonds in the same pentagon from a thermodynamic point of view. Based on the optimized neutral geometries, the vertical ionization potential and vertical electron affinity have been obtained. Meanwhile, the vibrational frequencies, IR spectrum, and 13C chemical shifts of various C24O2 isomers have been calculated and analyzed.

TAXAYUNTIN A,B,C AND D----FOUR NEW TETRACYCLIC TAXANES FROM TAXUS YUNNANENSIS

Four new taxane diterpenoids were isolated from the bark of Taxus yunnanensis.Their structures were elucidated as the new skeleton with 5/7/6/4 membered rings by spectral analysis and 2D NMR shift correlation experiments.

Viral hepatitis and hepatocellular carcinoma:From molecular pathways to the role of clinical surveillance and antiviral treatment

Hepatocellular carcinoma(HCC)is a global health challenge.Due to the high prevalence in low-income countries,hepatitis B virus(HBV)and hepatitis C virus infections remain the main risk factors for HCC occurrence,despite the increasing frequencies of non-viral etiologies.In addition,hepatitis D virus coinfection increases the oncogenic risk in patients with HBV infection.The molecular processes underlying HCC development are complex and various,either independent from liver disease etiology or etiology-related.The reciprocal interlinkage among non-viral and viral risk factors,the damaged cellular microenvironment,the dysregulation of the immune system and the alteration of gutliver-axis are known to participate in liver cancer induction and progression.Oncogenic mechanisms and pathways change throughout the natural history of viral hepatitis with the worsening of liver fibrosis.The high risk of cancer incidence in chronic viral hepatitis infected patients compared to other liver disease etiologies makes it necessary to implement a proper surveillance,both through clinical-biochemical scores and periodic ultrasound assessment.This review aims to outline viral and microenvironmental factors contributing to HCC occurrence in patients with chronic viral hepatitis and to point out the importance of surveillance programs recommended by international guidelines to promote early diagnosis of HCC.

The Alkaloids from Leaves of Croton hemiargyerius var. gymnodiscus

Aim Investigation of alkaloids from the leaves of Brazilian medicinal plantCroton hemiargyerius var. gymnodiscus. Methods Silica gel column chromatography was used repeatedlyfor the isolation and purification, and their structures were identified by extensive spectroscopyand comparison of the chemical and physical data with those of authentic samples reported inliterature. Results Twelve alkaloids were isolated and their structures were identified. ConclusionFour new alkaloids named hemiargines A (1), B (5), C (6) and D (7), together with eight knownalkaloids namely isoc-orydine (2), corydine (3), norcorydine (4), salutaridine (8), glaucine (9),tetrahydropalmatrubine (10), xylopinoine (11), and norlaudanosine (12) were isolated.

Two New C-glucoside Flavonoids from Leaves of Crataegus pinnatifida Bge.var.major N.E.Br.

Two new C-glucoside flavonoids, namely 8-C-b-D-(2-O-acetyl) glucofuranosyl apigenin and 3-O-acetylvitexin, were isolated from leaves of Crataegus pinnatifida Bge. var. major N. E. Br.. Their structures were elucidated by the spectroscopic means and chemical evidence.

Viral hepatitis in 2021:The challenges remaining and how we should tackle them

Viral hepatitis results in 1.4 million deaths annually.The World Health Organization(WHO)set an ambitious target to eliminate viral hepatitis by 2030,but significant challenges remain.These include inequalities in access to healthcare,reaching at risk populations and providing access to screening and effective treatment.Stigma around viral hepatitis persists and must be addressed.The WHO goal of global elimination by 2030 is a worthy aim,but remains ambitious and the coronavirus 2019 pandemic undoubtedly has set back progress.This review article will focus on hepatitis A to E,highlighting problems that have been resolved in the field over the past decade,those that remain to be resolved and suggest directions for future problem solving and research.

Platelet count as a screening tool for compensated cirrhosis in chronic viral hepatitis

BACKGROUND Simple tools for clinicians to identify cirrhosis in patients with chronic viral hepatitis are medically necessary for treatment initiation,hepatocellular cancer screening and additional medical management.AIM To determine whether platelets or other laboratory markers can be used as a simple method to identify the development of cirrhosis.METHODS Clinical,biochemical and histologic laboratory data from treatment naive chronic viral hepatitis B(HBV),C(HCV),and D(HDV)patients at the NIH Clinical Center from 1985-2019 were collected and subjects were randomly divided into training and validation cohorts.Laboratory markers were tested for their ability to identify cirrhosis(Ishak≥5)using receiver operating characteristic curves and an optimal cut-off was calculated within the training cohort.The final cut-off was tested within the validation cohort.RESULTS Overall,1027 subjects(HCV=701,HBV=240 and HDV=86),66%male,with mean(standard deviation)age of 45(11)years were evaluated.Within the training cohort(n=715),platelets performed the best at identifying cirrhosis compared to other laboratory markers[Area Under the Receiver Operating Characteristics curve(AUROC)=0.86(0.82-0.90)]and sensitivity 77%,specificity 83%,positive predictive value 44%,and negative predictive value 95%.All other tested markers had AUROCs≤0.77.The optimal platelet cut-off for detecting cirrhosis in the training cohort was 143×109/L and it performed equally well in the validation cohort(n=312)[AUROC=0.85(0.76-0.94)].CONCLUSION The use of platelet counts should be considered to identify cirrhosis and ensure optimal care and management of patients with chronic viral hepatitis.