Protein dynamics elucidated by NMR technique

In 1957,Christian Anfinsen postulated his famous dogma based on the study of ribonuclease(Sela et al.,1957),stating that the amino acid sequence of a protein determines its tertiary structure,a unique and kinetically accessible energy minimum,in a given environment.As a result,determination of a global energy minimum,or the most populated structure,has been the main focus of structural biology in the ensuing half a century.With more and more structures have been determined,people have gain some insights of why protein functions,but the detailed mechanisms and the function process,or how protein functions,remains elusive.

Single-cell multi-cohort dissection of the schizophrenia transcriptome

The complexity and heterogeneity of schizophrenia have hindered mechanistic elucidation and the development of more effective therapies.Here,we performed single-cell dissection of schizophrenia-associated transcriptomic changes in the human prefrontal cortex across 140 individuals in two independent cohorts.Excitatory neurons were the most affected cell group,with transcriptional changes converging on neurodevelopment and synapse-related molecular pathways.

An Isopropyldioxy Flavonol from Hypericum perforatum L.

Aim Isolation and structural elucidation of the constituents from the aerialpart of Hypericum perforatum L. Methods Column chromatography and TLC were used to isolate chemicalconstituents. Physico-chemical characterization and spectroscopic analysis were employed forstructural identification. Results Three flavonols were isolated and identified. Conclusion Compound1 is a novel natural product and its structure has been characterized to be 3, 5, 7-trihydroxy-3',4'-isopropyldioxy-flavone.

论杜预《春秋经传集解》(下)

Du Yu’s Annotation of Classics and Elucidations in "Spring and Autumn Annals" is considered as a milestone for the studies of Spring and Autumn Annals, In Du’s book, the Preface to the Spring and Autumn Annals is a theoretical summary and revision for the previous studies on the Spring and Autumn Annals and the Tso Chuan. Its combination of classics and elucidations makes Tso Chuan a real elucidating study on Spring and Autumn Annals. Du expounds his philosophy and political ideas in this book.

Crosstalk between adipose-derived stem cells and chondrocytes:when growth factors matter

Adipose-derived stem cells（ASCs）and mesenchymal stem cells are promising for tissue repair because of their multilineage differentiation capacity.Our previous data confirmed that the implantation of mixed ASCs and chondrocytes into cartilage defects induced desirable in vivo healing outcomes.However,the paracrine action of ASCs on chondrocytes needs to be further elucidated.In this study,we established a co-culture system to achieve cell-to-cell and cell-to-tissue crosstalk and explored the soluble growth factors in both ASCs and chondrocytes supplemented with 1%fetal bovine serum to mimic the physiological microenvironment.In ASCs,we screened for growth factors by semi-quantitative PCR and quantitative real-time PCR and found that the expression of bone morphogenetic protein 2（BMP-2）,vascular endothelial growth factor B（VEGFB）,hypoxia inducible factor-1α（HIF-1α）,fibroblast growth factor-2（FGF-2）,and transforming growth factor-β1 significantly increased after co-culture in comparison with mono-culture.In chondrocytes,VEGFA was significantly enhanced after co-culture.Unexpectedly,the expression of collagen II and aggrecan was significantly down-regulated in the co-culture group compared with the mono-culture group.Meanwhile,among all the growth factors screened,we found that the BMP family members BMP-2,BMP-4,and BMP-5 were down-regulated and that VEGFB,HIF-1α,FGF-2,and PDGF were significantly decreased after co-culture.These results suggest that crosstalk between ASCs and chondrocytes is a pathway through the regulated growth factors that might have potential in cartilage repair and regeneration and could be useful for tissue engineering.

Numerical Estimation of the Thermal Response of Thermal Protective Clothing-Air Gap-Human Skin Micro-system

Thermal protective clothing has been recognized as the primary shielding against emergency fire hazard and inflammable gas leakage. Therefore,the thermal response of human covered with thermal protective clothing under high temperature is the key work to investigate the thermal insulation of thermal protective clothing. A coupling model composed of thermal protective clothing,air gap and human skin is established and the temperature of the micro-system is numerically solved via the finite element method( FEM).Especially,the heat transfer of air gap located between clothing and human skin considering conduction and radiation is established while the human skin layers involve the effect of blood perfusion. Then the effect of thermophysical properties( thermal conductivity and volumetric capacity) of fabric and thickness of fabric and air on the thermal response of the micro-system is elucidated and compared.The results indicate that the volumetric heat capacity of fabric is the key parameter to affect the thermal shielding performance of thermal protective clothing,and the thicker fabric thickness and air gap thickness can improve the thermal protective properties of the micro-system.

PROGRESS OF RESEARCH ON ISCHEMIC STROKE TREATED WITH CHINESE MEDICINE

Ischemic stroke belongs to the categoryof apoplexy in Traditional Chinese Medicine(TCM)and TCM has accumulated a lot ofexperience in its treatment.Owing to pro-found experimental and clinical researches,the curative effects of TCM on apoplexyhave greatly improved and its mechanismhas been elucidated to a certain extent.

TREATMENT OF TRIGEMINAL NEURALGIA WITH ACUPUNCTURE AT RENYING POINT -A Report of 7 Cases

Trigeminal neuralgia refers to repeated paroxysmal, transient, and severe pain in the innervation area of the trigeminal nerve. The cause of this disease has not yet been fully elucidated. There is no special therapeutic measure to treat it. The authors have achieved relatively satisfactory curative effect in seven patients with trigeminal neuralgia by acupuncture at Renying point (St 9). This is reported as follows.

SPECIAL PROBLEMS IN ENVIRONMENTAL CARCINOGENESIS:CURRENT PROBLEMS IN THAILAND.

It is well documented that there are markeddifferences in the types of cancer between geographicalareas and between countries in the industrialized world andthe non-industrialized or developing countries.Thesedifferences may be attributed to the lifestyle,host-physiological and environmental factors (includingcarcinogens in the environment) rather than the geneticfactor.

Structure and function of the membrane microdomains in osteoclasts

The cell membrane structure is closely related to the occurrence and progression of many metabolic bone diseases observed in the clinic and is an important target to the development of therapeutic strategies for these diseases.Strong experimental evidence supports the existence of membrane microdomains in osteoclasts(OCs).However,the potential membrane microdomains and the crucial mechanisms underlying their roles in OCs have not been fully characterized.Membrane microdomain components,such as scaffolding proteins and the actin cytoskeleton,as well as the roles of individual membrane proteins,need to be elucidated.In this review,we discuss the compositions and critical functions of membrane microdomains that determine the biological behavior of OCs through the three main stages of the OC life cycle.

Mechanism of soft x-ray continuum radiation from low-energy pinch discharges of hydrogen and ultra-low field ignition of solid fuels

EUV continuum radiation（10–30 nm） arising only from very low energy pulsed pinch gas discharges comprising some hydrogen was first observed at Black Light Power, Inc. and reproduced at the Harvard Center for Astrophysics（Cf A）. The source was determined to be due to the transition of H to the lower-energy hydrogen or hydrino state H（1/4） whose emission matches that observed wherein alternative sources were eliminated. The identity of the catalyst that accepts 3 · 27.2 eV from the H to cause the H to H（1/4） transition was determined to HOH versus 3H. The mechanism was elucidated using different oxide-coated electrodes that were selective in forming HOH versus plasma forming metal atoms as well as from the intensity profile that was a mismatch for the multi-body reaction required during 3H catalysis. The HOH catalyst was further shown to give EUV radiation of the same nature by igniting a solid fuel comprising a source of H and HOH catalyst by passing a low voltage, high current through the fuel to produce explosive plasma. No chemical reaction can release such high-energy light. No high field existed to form highly ionized ions that could give radiation in this EUV region that persisted even without power input. This plasma source serves as strong evidence for the existence of the transition of H to hydrino H（1/4） by HOH as the catalyst and a corresponding new power source wherein initial extraordinarily brilliant light-emitting prototypes are already producing photovoltaic generated electrical power. The hydrino product of a catalyst reaction of atomic hydrogen was analyzed by multiple spectroscopic techniques. Moreover, the m H catalyst was identified to be active in astronomical sources such as the Sun, stars and interstellar medium wherein the characteristics of hydrino match those of the dark matter of the Universe.

Structural elucidation of a new cembranoid diterpene from the Chinese soft coral Sarcophyton sp.

To investigate the cembranoid diterpenes from the soft coral Sarcophyton sp. collected in the South China Sea. Repeatedly column chromatography was performed for the isolation and purification. The structures were elucidated on the basis of extensive spectral data （IR, MS, 1 D- and 2D-NMR） analysis by comparing with literature data. A new cembranoid diterpene namely sarcophyolide A （1）, together with 7a, 8β-dihydroxydeepoxysarcophine （2） were isolated from this species. The cembranoid diterpenes with 7-1actone could be chemotaxonomic markers of Sarcophyton sp.

NMR Spectral Analysis and Hydrolysis Studies of Rebaudioside N, a Minor Steviol Glycoside of <i>Stevia rebaudiana</i>Bertoni

The complete proton and carbon NMR spectral assignments of a diterpene glycoside isolated from the commercial extract of the leaves of Stevia rebaudiana Bertoni, 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] entkaur-16-en-19-oic acid-[(2-O-α-L-rhamnopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl) ester] (1);also known as rebaudioside N, was achieved by the extensive 1D and 2D NMR (1H and 13C, COSY, HMQC, HMBC) as well as mass spectral data. Further, hydrolysis studies were performed on rebaudioside N using acid and enzymatic studies to identify aglycone and sugar residues in its structure.

Furostanol Saponins from Asparagus cochinchinensis and Their Cytotoxicity

Phytochemical investigation on the roots of Asparagus cochinchinensis led to the isolation of one new furostanol saponin,named 26-O-β-d-glucopyranosyl-22α-hydroxyl-(25R)-Δ5(6)-furost-3β,26-diol-3-O-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→4)]-β-d-glucopyranoside(1),along with three known congeners(2‒4).The structure of new saponin was elucidated via comprehensive inspection of its HRMS and NMR spectral data as well as chemical technology,whereas those of known ones were identified by comparison of their NMR and MS spectral data with those reported in literatures.All isolated saponins were evaluated for their cytotoxic effects on two human liver(MHCC97H)and lung adenocarcinoma(H1299)cancer cells in vitro.Among them,both 1 and 2 showed significant cytotoxicity against above mentioned cell lines.Further studies revealed that these two saponins could significantly inhibit their proliferation of MHCC97H and H1299 cells.

A New Steroid from Polygonum nodosum Pers

A new steroid named as Zhonghualiaoine I (1) was isolated from Polygonum nodosum Pers (Chinese name 揨honghualiao? Berberidaceae). Its structure was deduced on the basis of its spectral data.

Residual Dipolar Couplings in Structure Determination of Natural Products

The determination of natural products stereochemistry remains a formidable task.Residual dipolar couplings(RDCs)induced by anisotropic media are a powerful tool for determination of the stereochemistry of organic molecule in solution.This review will provide a short introduction on RDCs-based methodology for the structural elucidation of natural products.Special attention is given to the current availability of alignment media in organic solvents.The applications of RDCs for structural analysis of some examples of natural products were discussed and summarized.Graphical Abstract This review provides a short introduction on RDCs-based methodology for the structural elucidation of natural products.Special attention is given to the current availability of alignment media in organic solvents.The applications of RDCs for structural analysis of some examples of natural products were discussed and summarized.

New Dammarane Triterpenoids,Caffruones A–D,from the Cherries of Coffea arabica

In present study,four new dammarane-type triterpenoids,namely caffruones A–D(1–4),were isolated from the cherries of Coffea arabica.Their structures were elucidated by extensive spectroscopic analysis including 1D,2D NMR(HSQC,HMBC,^(1)H–^(1)H COSY,and ROESY),HRMS and IR spectra.This is the first time that tetracyclic triterpenes have been reported in genus Coffea.

Characterization of New Ent-kaurane Diterpenoids of Yunnan Arabica Coffee Beans

Five new ent-kaurane diterpenoids,named mascaroside Ⅲ–Ⅴ(1–3),and 20-nor-cofaryloside Ⅰ–Ⅱ(4–5),together with seven known diterpenoids,were isolated from methanol extracts of the green coffee beans of Yunnan Arabica Coffee.Their chemical structures were elucidated by extensive spectroscopic analyses.Meanwhile,cytotoxicity assay against HL-60,A-549,SMMC-7721,MCF-7 and SW480 cell lines showed that they have not evident inhibition of cytotoxicity.

A new dimeric furanocoumarin from Notopterygium incisum

A new dimeric psoralen-type furanocoumarin, notopterol-（18-O-20＇）-notopol （1）, was isolated from Notopterygium incisum for the first time and its structure was elucidated by spectroscopic methods.

STUDIES ON THE CHEMICAL CONSTITUENTS OF CLAUSENA LANSIUM(LOUR.)SKEELS Ⅲ.The structural elucidation of homo-and zeta-clausenamide(1)

The structures of two novel lactams isolated from Clausena lansium were elucidated mainly on the bases of their spectral data. They are homoclausenamide(1),a -lactam,and zetaclausenamide(4), an eight-membered ring lactam.