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Oligosaccharides have myriad functions throughout biological processes1,2. Chemical synthesis of these structurally complex molecules facilitates investigation of their functions. With a dense concentration of stereocentres and hydroxyl groups, oligosaccharide assembly through O-glycosylation requires simultaneous control of site, stereo- and chemoselectivities3,4. Chemists have traditionally relied on protecting group manipulations for this purpose5-8, adding considerable synthetic work. Here we report a glycosylation platform that enables selective coupling between unprotected or minimally protected donor and acceptor sugars, producing 1,2-cis-O-glycosides in a catalyst-controlled, site-selective manner. Radical-based activation9 of allyl glycosyl sulfones forms glycosyl bromides. A designed aminoboronic acid catalyst brings this reactive intermediate close to an acceptor through a network of non-covalent hydrogen bonding and reversible covalent B-O bonding interactions, allowing precise glycosyl transfer. The site of glycosylation can be switched with different aminoboronic acid catalysts by affecting their interaction modes with substrates. The method accommodates a wide range of sugar types, amenable to the preparation of naturally occurring sugar chains and pentasaccharides containing 11 free hydroxyls. Experimental and computational studies provide insights into the origin of selectivity outcomes.
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Glicósidos , Oligosacáridos , Ácidos Borónicos/química , Bromuros/química , Catálisis , Glicósidos/química , Glicósidos/síntesis química , Glicosilación , Enlace de Hidrógeno , Oligosacáridos/química , Oligosacáridos/síntesis química , Sulfonas/químicaRESUMEN
Although the concerted [3 + 2] mechanism of osmium-catalyzed asymmetric dihydroxylation has been generally accepted, the unusual nonlinear Hammett relationship induced by amine-type ligands remains unexplained. To understand this, we carried out a density functional theory (DFT) study for the osmylation of substituted styrenes by the following: OsO4, OsO4-pyridine, OsO4-4-cyanopyridine, OsO4-4-pyrrolidinopyridine, and OsO4-quinuclidine. Calculations using the M06 functional successfully reproduce the experimentally observed nonlinear relationships. The transition states exhibit considerable singlet-diradical character, which causes the nonlinear Hammett relationship. Regardless of the presence or absence of an amine-type ligand, an electron donation from styrene to OsO4 is observed, indicating no mechanistic change. Calculations indicate that the electronic interaction between the amine-type ligand and styrene also influences the reaction rate.
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Due to boron's metalloid properties, aromatic boron reagents are prevalent synthetic intermediates. The direct borylation of aryl C-H bonds for producing aromatic boron compounds offers an appealing, one-step solution. Despite significant advances in this field, achieving regioselective aryl C-H bond borylation using simple and readily available starting materials still remains a challenge. In this work, we attempted to enhance the reactivity of the electron-donor-acceptor (EDA) complex by selecting different bases to replace the organic base (NEt3) used in our previous research. To our delight, when using NH4HCO3 as the base, we have achieved a mild visible-light-mediated aromatic C-H bond borylation reaction with exceptional regioselectivity (rr > 40:1 to single isomers). Compared with our previous borylation methodologies, this protocol provides a more efficient and broader scope for aryl C-H bond borylation through the use of N-Bromosuccinimide. The protocol's good functional-group tolerance and excellent regioselectivity enable the functionalization of a variety of biologically relevant compounds and novel cascade transformations. Mechanistic experiments and theoretical calculations conducted in this study have indicated that, for certain arenes, the aryl C-H bond borylation might proceed through a new reaction mechanism, which involves the formation of a novel transient EDA complex.
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This paper aims to explore the effect of Xuming Decoction in the Records of Proved Prescriptions, Ancient and Modern on cerebral ischemic injury and angiogenesis in the rat model of acute cerebral infarction. SD rats were randomized into 6 groups: sham group, model group, low-, medium-, and high-dose(5.13, 10.26, and 20.52 g·kg~(-1), respectively) Xuming Decoction groups, and butylphthalide(0.06 g·kg~(-1)) group. After the successful establishment of the rat model by middle cerebral artery occlusion(MCAO), rats in the sham and model groups were administrated with distilled water and those in other groups with corresponding drugs for 7 consecutive days. After the neurological function was scored, all the rats were sacrificed, and the brain tissue samples were collected. The degree of cerebral ischemic injury was assessed by the neurological deficit score and staining with 2,3,5-triphenyltetrazolium chloride. Hematoxylin-eosin staining was performed to observe the pathological changes in the brain. Transmission electron microscopy was employed to observe the ultrastructures of neurons and microvascular endothelial cells(ECs) on the ischemic side of the brain tissue. Immunofluorescence assay was employed to detect the expression of von Willebrand factor(vWF) and hematopoietic progenitor cell antigen CD34(CD34) in the ischemic brain tissue. Real-time PCR and Western blot were employed to determine the mRNA and protein levels, respectively, of Runt-related transcription factor 1(RUNX1), vascular endothelial growth factor(VEGF), angiopoietin-1(Ang-1), angiopoietin-2(Ang-2), and VEGF receptor 2(VEGFR2) in the ischemic brain tissue. The results showed that compared with the sham group, the model group showed increased neurological deficit score and cerebral infarction area(P<0.01), pathological changes, and damaged ultrastructure of neurons and microvascular ECs in the ischemic brain tissue. Furthermore, the modeling up-regulated the mRNA levels of RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P<0.01) and the protein levels of vWF, CD34, RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P<0.05 or P<0.01). Compared with the model group, high-dose Xuming Decoction and butylphthalide decreased the neurological deficit score and cerebral infarction area(P<0.01) and alleviated the pathological changes and damage of the ultrastructure of neurons and microvascular ECs in the ischemic brain tissue. Moreover, they up-regulated the mRNA levels of RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P<0.01) and the protein levels of vWF, CD34, RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P<0.01). The results suggest that Xuming Decoction in the Records of Proved Prescriptions, Ancient and Modern can promote the angiogenesis and collateral circulation establishment to alleviate neurological dysfunction of the ischemic brain tissue in MCAO rats by regulating the RUNX1/VEGF pathway.
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Isquemia Encefálica , Infarto Cerebral , Modelos Animales de Enfermedad , Medicamentos Herbarios Chinos , Ratas Sprague-Dawley , Animales , Ratas , Masculino , Medicamentos Herbarios Chinos/farmacología , Infarto Cerebral/tratamiento farmacológico , Infarto Cerebral/metabolismo , Infarto Cerebral/genética , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/metabolismo , Isquemia Encefálica/genética , Humanos , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Neovascularización Fisiológica/efectos de los fármacos , Angiopoyetina 2/genética , Angiopoyetina 2/metabolismo , AngiogénesisRESUMEN
We employed bibliometrics to comprehensively study the hotspots and frontiers of gut microbiota research involving traditional Chinese medicine(TCM), aiming to provide new ideas for the subsequent research in this field. The studies of gut microbiota with TCM published from January 1, 2002 to December 31, 2021 were retrieved from CNKI, Wanfang, VIP and Web of Science(WoS). After data screening and cleaning, CiteSpace 5.8.R3 was used to visualize and analyze the authors, journals, and keywords. A total of 1 119 Chinese articles and 815 English articles were included in the study. The period of 2019-2021 witnessed the surge in the number of articles published in this field, being the peak research period. TAN Zhou-jin and DUAN Jin-ao were the authors publishing the most articles in Chinese and English, respectively. The two authors ranked top in both Chinese and English articles, playing a central role in this research field. The top five Chinese and English journals in this field had a large influence in the international research field. High-frequency keywords and keyword clustering showed that the research hotspots in this field were concentrated in four areas: trial and clinical research on the regulation of gut microbiota in disease treatment by TCM, metabolic transformation of Chinese medicines by gut microbiota, and the effect of TCM added to feed on the gut microbiota and growth performance of animals. The study of gut microbiota structure in patients with different TCM syndromes, as well as that of TCM combined with probiotics/flora transplantation in the treatment of diseases, can provide new ideas for clinical diagnosis and traditional drug treatment of diseases and has great research space and research value in the future.
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Microbioma Gastrointestinal , Medicina Tradicional China , Animales , Publicaciones , BibliometríaRESUMEN
The study was conducted by searching the literature related to the regulation of necroptosis with Chinese medicine from January 1, 2005 to December 31, 2021 in CNKI, VIP, Wanfang, Web of Science(WoS), and PubMed. The obtained literature were imported into NoteExpress for eliminating duplicates and screening, and the final included articles were imported into Excel to plot the publication trend. The core authors were identified according to Price's law, and VOSviewer 1.6.17 was used to draw a collaborative view of the core authors and sort the high-frequency keywords. Then CiteSpace 5.8.R3 was employed to analyze keywords clustering, burst, and timeline view. Finally, 98 Chinese articles and 72 English articles were included in the study. The number of publications on the regulation of necroptosis with Chinese medicine has been increasing year by year. China ranked among the top in the world in terms of the number of publications, and Chinese authors played a central role in this field. Specifically, LIU Hua published the most Chinese literature while CHEN X P had the most English publications. The collaborative view of the core authors showed more intra-team cooperation and less inter-team cooperation. The Chinese and English keywords formed ten clusters separately, indicating that the research hotspots of regulation of necroptosis with Chinese medicine mainly focused on disease, prescription, related factors, and mecha-nism. Further, the analysis of Chinese and English keywords revealed that regarding disease treatment, tumor, ischemia-reperfusion injury, neurodegenerative diseases, and inflammatory diseases were studied most. The Chinese medicines that received much attention in this field were curcumin, shikonin and tanshinone. The main protein factors involved were Ripk1, Ripk3, Mlkl, and TNF-α, and Ripk1/Ripk3/Mlkl and p53 signaling pathways were predominant. Moreover, single herbs and herbal monomers were the hotspots of the included articles. In the future, scholars need to expand the study of classical Chinese herbal compounds and explore their mechanism of action in the occurrence and development of various diseases, to provide new ideas and experimental basis for the treatment of clinical diseases with Chinese medicine.
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Medicina Tradicional China , Necroptosis , China , Reconocimiento de Normas Patrones AutomatizadasRESUMEN
MicroRNA (miR) is important regulators of gene expression, and aberrant miR expression has been linked to oncogenesis; however, little is understood about their contribution to colorectal cancer (CRC). Here, we determined that miR-23a is overexpressed in human colorectal cancer cell lines and tissues compared with that of normal cells. The stable over-expression of miR-23a in CRC cells was sufficient to promote cell proliferation in vitro and in vivo. Further studies showed that miR-23a can directly bind to the 3'untranslated region (3'UTR) of PDK4 mRNA and subsequently repress both the mRNA and protein expressions of PDK4. PDK4 negatively regulate CRC proliferation via suppressing PDH activity. Ectopic expression of PDK4 by transiently transfected with PDK4 vector encoding the entire coding sequence could reverse the effects of miR-23a on CRC proliferation. By this way, miR-23a promotes PDH activation and oxidative phosphorylation to generate sufficient ATP for cell proliferation. Our results illustrated that the up-regulation of miR-23a played an important role in CRC cell proliferation through direct repressing PDK4, suggesting a potential application of miR-23a in prognosis prediction and therapeutic application in CRC.
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Neoplasias Colorrectales/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Animales , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular , Neoplasias Colorrectales/enzimología , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Humanos , Masculino , Ratones Endogámicos BALB C , Ratones Desnudos , Mitocondrias/metabolismo , Fosforilación Oxidativa , Proteínas Serina-Treonina Quinasas/metabolismo , Piruvato Deshidrogenasa (Lipoamida)/metabolismo , Piruvato Deshidrogenasa Quinasa Acetil-TransferidoraRESUMEN
A large number of experimental and clinical data indicates that tumor-associated macrophages(TAMs) were involved in the whole process of tumor growth, invasion and metastasis. Like macrophages in other tissues, TAMs originate from blood monocytes, which are recruited to the tumor tissues by cytokines and then differentiated into TAMs. It is interesting that the monocytes overexpress siglec receptor in their surface, which has a high binding specificity to sialic acid(SA). From this point of view, we hypothesize that if SA was used as a ligand in the surfaces of drug delivery systems, SA would enhance the targeting efficiency to monocytes, and thus to achieve a higher specificity to TAMs. In our previous study, an SA derivative of SA-octadecylamine(SA-18) was synthesized and was found to enhance cytotoxicity on TAMs in vitro. The chain length is a critical factor for SA efficiency in liposomes and it has a significant influence on the TAM targeting effects of the carriers. So in this study, four kinds of different chain length of SA fatty amine derivatives were synthesized, including SA-18, SA-hexadecylamine(SA-16), SA-tetradecylamine(SA-14) and SA-dodecylamine(SA-12), and were modified on the surfaces of blank liposomes(BLK-Sn L, n = 18, 16, 14, 12) and pixantrone maleate-loaded liposomes(Pix-Sn L, n = 18, 16, 14, 12). TAM targeting effects of these SA derivatives were evaluated by acute toxicity and antitumor efficacy in vivo. The results of acute toxicity experiments showed that the toxicities of the SA derivatives deceased gradually with the reduction in the length of lipophilic chain. The in vivo antitumor efficacies of SA-modified blank liposomes showed that these blank formulations had no effect on the tumor inhibition except BLK-S14L(61.4% ± 18.8%), and BLK-S16 L even promoted the tumor growth(-31.7% ± 13.1%, the 18 th day). The in vivo antitumor efficacies of SA-modified Pix liposomes showed that the tumor inhibition effects were Pix-S18L(97.4% ± 2.1%) > Pix-S14L(73.1% ±21.1%) > Pix-S12L(53.9% ± 17.8%) > Pix-S16L(32.9%). Because of the relatively strong binding ability of SA-18, it was hard to fall off from the liposomes in the transport process, leading to a good TAM targeting ability and less toxicity to the normal tissues. Meanwhile, 50% of the mice in Pix-S18 L group showed "tumor shedding" and "wound healing" phenomena without recurrence in two months following the treatment. Therefore, SA-18 is the most potential TAM targeting material among these SA fatty amine derivatives.
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Sistemas de Liberación de Medicamentos , Liposomas , Macrófagos/efectos de los fármacos , Ácido N-Acetilneuramínico/química , Neoplasias/tratamiento farmacológico , Aminas , Animales , Línea Celular Tumoral , Composición de Medicamentos , Humanos , Hidrocarburos , RatonesRESUMEN
Investigation on the EtOAc extract of the bark of Zanthoxylum simulans led to the isolation of four new lignans including zanthoxylumin A (1), zanthoxylumin B (2), ( - )-magnolin (3), and ( - )-pinoresinol-di-3,3-dimethylallyl ether (4). Their structures were established by comprehensive analysis of the spectral data, especially 1D and 2D NMR spectra.
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Medicamentos Herbarios Chinos/aislamiento & purificación , Lignanos/aislamiento & purificación , Zanthoxylum/química , Medicamentos Herbarios Chinos/química , Lignanos/química , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Corteza de la Planta/químicaRESUMEN
Polyethylene glycol (PEG) is extensively used to increasing the in vivo and in vitro stability of liposomes. However, PEGylated liposomes also produce some negative effects with further research, such as low cellular uptake, poor "endosomal escape" of pH sensitive liposome (PSL) and accelerated blood clearance (ABC) phenomenon, and this situation is referred as the "PEG dilemma". "PEG dilemma" posed severe challenges for the targeted delivery of PEGylated liposomes-loaded anticancer drugs, effective intracellular release of PEGylated PSL-encapsulated gene and protein drugs, and repeated administration of PEGylated liposomes. Therefore, it is urgent to solve the "PEG dilemma". This review focused on the definition, classification of "PEG dilemma", and discussed several possible approaches to overcome "PEG dilemma".
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Portadores de Fármacos/química , Liposomas/química , Polietilenglicoles/química , Antineoplásicos/químicaRESUMEN
Investigation of the bark of Zanthoxylum simulans afforded six new dimeric lignans zanthpodocarpins C-H (1-6) bearing an unusual α,ß-unsaturated ketone group. The new structures of 1-6 were determined by using detailed spectroscopic analysis. All of the isolated compounds were examined for their inhibitory effects against rat joint synovial cell and splenocyte proliferation. Compounds 1-6 showed potent anti-inflammatory activities with IC50 values ranging from 18.6 to 36.1µM, and 13.8 to 74.3µM.
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Antiinflamatorios no Esteroideos/farmacología , Cetonas/química , Lignanos/farmacología , Bazo/efectos de los fármacos , Líquido Sinovial/efectos de los fármacos , Zanthoxylum/química , Animales , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/aislamiento & purificación , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/patología , Proliferación Celular/efectos de los fármacos , Dimerización , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Cetonas/aislamiento & purificación , Lignanos/química , Lignanos/aislamiento & purificación , Ratas , Bazo/patología , Relación Estructura-ActividadRESUMEN
Gestational diabetes mellitus (GDM) is a common complication that occurs during pregnancy. Emerging evidence suggests that immune abnormalities play a pivotal role in the development of GDM. Specifically, regulatory T cells (Tregs) are considered a critical factor in controlling maternal-fetal immune tolerance. However, the specific characteristics and alterations of Tregs during the pathogenesis of GDM remain poorly elucidated. Therefore, this study aimed to investigate the changes in Tregs among pregnant women diagnosed with GDM compared to healthy pregnant women. A prospective study was conducted, enrolling 23 healthy pregnant women in the third trimester and 21 third-trimester women diagnosed with GDM. Participants were followed up until the postpartum period. The proportions of various Treg, including Tregs, mTregs, and nTregs, were detected in the peripheral blood of pregnant women from both groups. Additionally, the expression levels of PD-1, HLA-G, and HLA-DR on these Tregs were examined. The results revealed no significant differences in the proportions of Tregs, mTregs, and nTregs between the two groups during the third trimester and postpartum period. However, GDM patients exhibited significantly reduced levels of PD-1+ Tregs (P < 0.01) and HLA-G+ Tregs (P < 0.05) in the third trimester compared to healthy pregnant women in the third trimester. Furthermore, GDM patients demonstrated significantly lower levels of PD-1+ mTregs (P < 0.01) and HLA-G+ (P < 0.05) mTregs compared to healthy pregnant women in the third trimester. Overall, the proportion of Tregs did not exhibit significant changes during the third trimester in GDM patients compared to healthy pregnant women. Nevertheless, the observed dysregulation of immune regulation function in Tregs and mTregs may be associated with the development of GDM in pregnant women.
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Diabetes Gestacional , Humanos , Embarazo , Femenino , Linfocitos T Reguladores , Receptor de Muerte Celular Programada 1 , Estudios Prospectivos , Antígenos HLA-GRESUMEN
We reported a novel electron-donor-acceptor (EDA) photocatalyst formed in situ from isoquinoline, a diboron reagent, and a weak base. To further optimize the efficiency of this photocatalyst, Density Functional Theory (DFT) calculations were conducted to investigate the substituent effects on the properties of vertical excitation energy and redox potential. Subsequently, we experimentally validated these effects using a broader range of substituents and varying substitution positions. Notably, the 4-NH2 EDA complex derived from 4-NH2-isoquinoline exhibits the highest photocatalytic efficiency, enabling feasible metal free borylation of aromatic C-H bond and detosylaion of Ts-anilines under green and super mild conditions. These experimental results demonstrate the effectiveness of our strategy for photocatalyst optimization.
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Based on a critical examination of type specimens, images of living plants, and the literature has shown Rhododendronoligocarpum to be conspecific with R.leishanicum. Although slight variations in corolla colour exist amongst different populations of R.oligocarpum, it does not serve as a key distinguishing trait. Therefore, we reduced R.oligocarpum to a synonym of R.leishanicum, and recommend placing it in Subsection Maculifera.
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The current study aims to develop a stable pH-sensitive drug delivery system. First, cleavable polyethylene glycol-α-tocopherol hemisuccinate (PEG-THS) was synthesized. Conventional pH-sensitive vesicles composed of the Tris salt of α-tocopherol hemisuccinate (THST) were then prepared using the detergent removal technique. The vesicles had a mean particle size of (163.8 ± 5.5) nm and a zeta potential of -74.5 ± 6.4 mV. The THST vesicles were then modified using PEG-THS or uncleavable PEG-cholesterol (PEG-CHOL) (THST/PEG-lipids, 100:6 molar ratio). The mean vesicle particle size and absolute zeta potential decreased with increasing PEG-THS proportion. When the pH was decreased, the vesicle particle size and calcein release rate increased. The THST vesicles were initially Ca(2+)-unstable but exhibited significantly improved stability after modification with PEG-THS, especially at PEG-lipid ratios above 6%. Incubation in an acid serum increased the calcein release rate of conventional THST vesicles to 45 ± 1.98% at 10 min. However, the release rate of the PEG-CHOL vesicles remained low. The calcein release rate of PEG-THS vesicles was between those of conventional and PEG-CHOL-V. Therefore, PEG-THS can protect vesicles in serum and reconstitute their pH sensitivity in acidic conditions. Cleavable PEG-THS can be used in stable pH-sensitive preparations without loss of pH sensitivity. Free calcein and conventional vesicles eliminated from the plasma soon after injection, as well as the half-life (t(1/2)) and area under the curve of PEG-THS-V encapsulating calcein, were dramatically increased. This phenomenon indicates that the use of PEG-lipid derivatives has gained a favorably long circulation effect in mice.
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Polietilenglicoles/química , alfa-Tocoferol/administración & dosificación , alfa-Tocoferol/química , Animales , Área Bajo la Curva , Tampones (Química) , Calcio/química , Colesterol/química , Sistemas de Liberación de Medicamentos/métodos , Estabilidad de Medicamentos , Fluoresceínas/química , Semivida , Concentración de Iones de Hidrógeno , Lípidos/química , Masculino , Ratones , Tamaño de la Partícula , Polietilenglicoles/administración & dosificación , Polietilenglicoles/farmacocinética , Suero/química , Soluciones/química , alfa-Tocoferol/farmacocinéticaRESUMEN
BACKGROUND: The Buyang Huanwu Decoction (BYHWD) originated from Wang Qingren's "Yi Lin Gai Cuo". It has the effect of tonifying qi and activating blood circulation and dredging collaterals which is recommended for the treatment of Ischemic stroke in China. In recent years, there have been many systematic reviews of Ischemic stroke treated by BYHWD assessing the efficacy of BYHWD in the treatment of Ischemic stroke in the acute, convalescent and sequelae stages. Because of the different methods of analysis, the quality and quality of the evidence obtained in these systematic reviews is different, so a systematic re-evaluation was needed to comprehensively evaluate the strength of these studies. METHODS: Systematic reviews and meta-analyses of Ischemic stroke treated by BYHWD were identified through the Web of Science, PubMed, CNKI, Weipu, and Wanfang databases. The included studies were selected for literature screening, methodological quality evaluation, and evidence level evaluation by two investigators. The methodological quality was evaluated by the 2020 PRISMA guidelines, Assessing the Methodological Quality of Systematic Reviews (AMSTAR) scale, and the evidence quality was evaluated by the GRADE criteria. RESULTS: Overall, 12 studies involving 28,594 patients between 2006-2021 were included in this analysis. The methodological quality evaluation based on 2020 PRISMA guidelines results showed that there were many weaknesses in registration and protocol, support, competing interests, competing interests and availability of data, code and other materials. The AMSTAR scale evaluation results showed that the 12 studies were very low quality. The results of the GRADE criteria evaluation showed that the quality of the evidence was scattered, with mainly low-quality evidence. CONCLUSION: The methodological quality of systematic reviews and meta-analyses of BYHWD in treating Ischemic stroke was generally poor, and the quality of evidence was generally low.
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Medicamentos Herbarios Chinos , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , China , HumanosRESUMEN
Organoboron compounds are very important building blocks which can be applied in medicinal, biological and industrial fields. However, direct borylation in a metal free manner has been very rarely reported. Herein, we described the successful direct borylation of haloarenes under mild, operationally simple, catalyst-free conditions, promoted by irradiation with visible light. Mechanistic experiments and computational investigations indicate the formation of an excited donor-acceptor complex with a -3.12 V reduction potential, which is a highly active reductant and can facilitate single-electron-transfer (SET) with aryl halides to produce aryl radical intermediates. A two-step one-pot method was developed for site selective aromatic C-H bond borylation. The protocol's good functional group tolerance enables the functionalization of a variety of biologically relevant compounds, representing a new application of aryl radicals merged with photochemistry.
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Described herein is the development of a metal-free iodide-catalyzed radical reductive cyclization of 1,6-enynes. A strategy involving in situ iodination/radical cyclization/silyl radical-mediated halogen atom transfer/hydrogen atom transfer for the synthesis of functionalized pyrrolidines has been proposed. Using this halogen-atom abstraction protocol, 1,6-enynes with various vinyl halides including inert fluorides, chlorides, and reactive bromides could be transformed into substituted pyrroles via a multistep radical isomerization process.
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It is reported that polyethylene glycol-lipid (PEG-lipid) derivatives increase liposomes stability, prolong the blood circulation of liposomes, enhance their tumor-targeting efficiency, and improve drug efficacy. Therefore, it is of great importance to investigate the influence of modified PEG-lipid derivatives on the physical, chemical, and biological characteristics of liposomes for the promotion of dealing with the existed problems, such as the accelerated blood clearance (ABC) phenomenon when repeated intravous injection at a certain time-interval, and developing novel targeted pharmaceutical preparations. In this review, the effects of modified PEG-lipid derivatives were summarized in many aspects. It indicats that the chemical bonds (amide, ether, ester, and disulfide) between PEG and lipid, as well as the species of lipids, such as the commonly used phosphatidylethanolamine, cholesterol, and diacylglycerol have substantial effects on the grafted liposomes stability in vitro and in vivo. Besides, the properties of lipids (the fatty acid chain length and saturation) and the groups (methoxy, carboxylic and amino) at the distal ends of the PEG chains were also considered to be important factors. In the end, the influence of the average molecular weight of PEG and the molar ratio of PEG-lipid derivatives in the total lipid were further focused.
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Colesterol/química , Sistemas de Liberación de Medicamentos/métodos , Liposomas/química , Polietilenglicoles/química , Estabilidad de Medicamentos , Ácidos Grasos/química , Liposomas/farmacocinética , Fosfatidiletanolaminas/químicaRESUMEN
OBJECTIVE: We conducted a systematic review and meta-analysis to evaluate the curative effect of probiotics combined with enteral nutrition (EN) in patients with stroke. METHODS: We retrieved randomized controlled trials and case-controlled trials on the use of probiotics for stroke treatment from PubMed, Web of Science, CNKI, Wanfang, and Weipu databases. Retrieval times were from the databases' inception to November 6, 2020. Two researchers conducted a strict evaluation of the literature quality and extracted the data, which were then entered into RevMan 5.3 for meta-analysis. RESULTS: Twenty-three articles were included, including 1,816 patients. The meta-analysis revealed that probiotics combined with EN did not reduce NIHSS scores of patients with stroke (P > 0.05). However, it did shorten hospital stays and bedrest periods (P < 0.05). Probiotics combined with EN also improved patients' nutritional status and increased hemoglobin, albumin, serum total protein, and physical and chemical properties of prealbumin (P < 0.05). In terms of relieving inflammation, we found that probiotics combined with EN reduced neither high-sensitivity C-reactive protein nor procalcitonin (P > 0.05). However, it did cause a significant reduction in TNF-α, IL-6, and IL-10. Probiotics combined with EN significantly reduced esophageal reflux, bloating, constipation, diarrhea, gastric retention, and gastrointestinal bleeding. It relieved intestinal stress and reduced the occurrence of adverse reactions such as esophageal reflux, bloating, constipation, diarrhea, gastric retention, and gastrointestinal bleeding (P < 0.05). In terms of reducing stroke complications, probiotics combined with EN reduced the incidence of lung, gastrointestinal, and urinary tract infections (P < 0.05). It also reduced fatality rates and intestinal flora imbalance rates (P < 0.05). CONCLUSION: The probiotics combined with EN group's therapeutic effects were superior to those of the EN alone. Thus, probiotics combined with EN is worthy of both clinical application and promotion in stroke treatment.