Enhancement of lateral Casimir force on a rotating particle near hyperbolic metamaterial.

Enhancement of weak Casimir forces is extremely important for their practical detection and subsequent applications in variety of scientific and technological fields. We study the lateral Casimir forces acting on the rotating particles with small radius of 50 nm as well as that with large radius of 500 nm near the hyperbolic metamaterial made of silicon carbide (SiC) nanowires. It is found that the lateral Casimir force acting on the small particle of 50 nm near hyperbolic metamaterial with appropriate filling fraction can be enhanced nearly four times comparing with that acting on the same particle near SiC bulk in the previous study. Such enhancement is caused by the coupling between the resonance mode excited by nanoparticle and the hyperbolic mode supported by hyperbolic metamaterial. The results obtained in this study provide an efficient method to enhance the interaction of nanoscale objects.

The impact of height on the spread of spinal anesthesia and stress response in parturients undergoing caesarean section: a prospective observational study.

BACKGROUND: The spread of spinal anesthesia was influenced by many factors, and the effect of body height on spinal anesthesia is still arguable. This study aimed to explore the impact of height on the spread of spinal anesthesia and the stress response in parturients. METHODS: A total of ninety-seven parturients were allocated into two groups according to their height: the shorter group (body height was shorter than 158 cm) and taller group (body height was taller than 165 cm). Spinal anesthesia was performed with the same amount of 12 mg plain ropivacaine in mothers of different heights. The primary outcome of the study was the success or failure of the spinal anesthesia. The secondary outcomes of the study were stress response, time to T6 sensory level, the incidence of hypotension, the satisfaction of abdominal muscle relaxation and patient VAS scores. RESULTS: The rate of successful spinal anesthesia in the shorter group was significantly higher than that in the taller group (p = 0.02). The increase of maternal cortisol level in the shorter group was lower than that in the taller group at skin closure (p = 0.001). The incidence of hypotension (p = 0.013), time to T6 sensory block (p = 0.005), the quality of abdominal muscle relaxation (p <  0.001), and VAS values in stretching abdominal muscles and uterine exteriorization (p <  0.001) in the shorter group were significantly different from those in the taller group. Multivariate analysis showed that vertebral column length (p <  0.001), abdominal girth (p = 0.022), amniotic fluid index (p = 0.022) were significantly associated with successful spinal anesthesia. CONCLUSIONS: It's difficult to use a single factor to predict the spread of spinal anesthesia. Patient's vertebral column length, amniotic fluid index and abdominal girth were the high determinant factors for predicting the spread of spinal anesthesia. TRIALS REGISTRATION: ChiCTR-ROC-17012030 ( Chictr.org.cn ), registered on 18/07/2017.

Oxime-Based and Catalyst-Free Dynamic Covalent Polyurethanes.

Polyurethanes (PUs) have many applications resulting from their preeminent properties, but being commonly used toxic catalysts, and the lack of processability for PU thermosets cause limitations. Herein, we report a new class of the PU-like dynamic covalent polymers, poly(oxime-urethanes) (POUs), which are prepared from the uncatalyzed polyaddition of multifunctional oximes and hexamethylene diisocyanate (HDI) at ambient temperature. Kinetics studies reveal that almost complete polymerization (∼99% conversion) can be achieved in 3 h at 30 °C in dichloromethane (DCM), the most effective among the solvents evaluated, producing linear POUs with comparable molecular weights to the catalyzed PUs. We find that the oxime-carbamate structures are reversible at about 100 °C through oxime-enabled transcarbamoylation via a thermally dissociative mechanism. The cross-linked POUs based on oxime-carbamate bonds show efficient catalyst-free healable/recyclable properties. Density functional theory (DFT) calculations suggest that the fast oxime-urethanation and the mild thermoreversible nature are mediated by the characteristic nitrone tautomer of the oxime. Given widespread urethane-containing materials, POUs are of promising potential in applications because of the excellent mechanical performances, facile preparation, and dynamic property without using catalysts.

Fibrin sealant before wound closure in total knee arthroplasty reduced blood loss: a meta-analysis.

PURPOSE: Fibrin sealant (FS) comprises a mixture of fibrinogen and thrombin that controls bleeding, reduces blood transfusions, improves tissue healing and shortens postoperative recovery time after various surgical procedures. However, no single study has been large enough to definitively determine whether fibrin sealant is safe and effective. We report a meta-analysis of randomized controlled trials (RCTs) evaluating the efficacy and safety of fibrin sealant in total knee arthroplasty. METHODS: Articles published before August, 2012 were identified from PubMed, Embase, The Cochrane Library and other internet databases. Relevant journals and the recommendations of expert panels were also searched manually. We included only high-quality RCTs. Two independent reviewers searched and assessed the literature. Relevant data were analysed using RevMan 5.0. RESULTS: Seven RCTs met the inclusion criteria. Use of fibrin sealant significantly reduced haemoglobin decline mean difference (MD = -0.72), 95 % confidence interval [95 % CI (-0.83, -0.62), p < 0.00001], postoperative drainage volume [MD = -354.53, 95 % CI (-482.43, -226.63), p < 0.00001], the proportion of patients requiring blood transfusion risk differences [RD = -0.27, 95 % CI (-0.45, -0.08), p = 0.006] and the incidence of wound haematoma [RD = -0.11, 95 % CI (-0.22, -0.00), p = 0.04]. There were no significant differences in deep vein thrombosis, pulmonary embolism, infection rate or other complications between groups. CONCLUSIONS: Use of fibrin sealant in total knee arthroplasty was effective and safe, reduced haemoglobin decline, postoperative drainage volume, incidence of haematoma and need for blood transfusion, and did not increase the risk of complications. Due to the limited quality of the evidence currently available, more high-quality RCTs are required. LEVEL OF EVIDENCE: II.

[Chemical constituents from Perovskia atriplicifolia].

An investigation on the chemical constituents of the 90% EtOH extract of Perovskia atriplicifolia led to the isolation of fifteen compounds from the EtOAc fraction. Based on the detailed spectral analysis (MS, 1D and 2D NMR), as well as comparison with the literatures, the structures of compounds 1-15 were determined as cirsimaritin (1), salvigenin (2), syringaldehyde (3), vinyl caffeate (4), 2α, 3α-dihydroxyolean-12-en-28-oicacid (5), 2α, 3α-dihydroxyurs-12-en-28-oicacid (6), niga-ichigoside F1 (2α, 3ß, 19α, 23- tetrahydroxyurs - 12-en-28-oicacid- O-ß-D- glucopyranoside, 7), sericoside (8), 4-epi-niga-ichigoside F1 (2α, 3ß, 19α, 24-tetrahydroxyurs-12-en-28-oicacid O-ß-D-glucopyranoside, 9), 2α, 3ß, 24-trihydroxyolean-12-en-28-oicacid O-ß-D-glucopyranosyl-(1 --> 2) - ß-D-glucopyranoside (10), pruvuloside A (11), asteryunnanoside A [2α, 3ß, 23-trihydroxyolean-12-en-28-oicacid O-ß-D-glucopyranosyl-(1 --> 2)-ß- D- glucopyranoside,12], rosmarinic acid methyl ester (13), ß-sitosterol (14), and daucosterol (15), respectively. Compounds 1-13 were isolated from the Perovskia genus for the first time. All the compounds were obtained from P. atriplicifolia for the first time.

Two new triterpenoids from the stems of Euphorbia royleana.

Two new triterpenoids, namely 24-methylene-5,24-dien-19(10→9)-abeo-8α,9ß,10α-eupha-3ß-ol (1) and 24-methyl-5,23-dien-19(10→9)-abeo-8α,9ß,10α-eupha-3ß-ol (2) were isolated from the stems of Euphorbia royleana, together with three known analogs. The structures of the new compounds were elucidated by extensive 1H NMR,13C NMR, HSQC, HMBC, 1H-1H COSY, ROESY and HR-MS spectroscopic analyses.

Direct syntheses of spiro- and fused-hydrofurans by a tunable tandem semipinacol rearrangement/oxa-Michael addition protocol.

A highly chemoselective one-pot reaction has been developed involving a tandem semipinacol rearrangement/oxa-Michael addition sequence in which the in situ generated ketol diene intermediate can be transformed specifically to either the spiro- or fused-dihydrofuran products (see scheme). This one-pot tandem reaction represents a general synthetic methodology for the syntheses of the two different kinds of furan derivatives.

A new ingol diterpenoid from the seeds of Euphorbia marginata Pursh.

A new ingol diterpenoid, namely 3-de-O-acetyleuphornan R (1), along with two known analogues, euphornans E (2) and N (3) were isolated from the seeds of Euphorbia marginata Pursh. The structure of 1 was elucidated by extensive 1H NMR, 13C NMR, HSQC, HMBC, and 1H-1H COSY, and HR-MS spectroscopic analyses.

The effect of staggered administration of zinc sulfate on the pharmacokinetics of oral cephalexin.

AIMS: To investigate the effect of zinc sulfate on pharmacokinetics of cephalexin when administered concurrently or at strategically spaced dosing times designed to avoid the potential interaction in healthy volunteers. METHODS: In this study, all subjects (n= 12) were randomized to receive the following four treatments, separated by a wash-out period of 7 days: cephalexin 500mg alone, concomitantly with zinc 250mg, 3h after zinc 250mg or 3h before zinc 250mg. RESULTS: All subjects completed the study safely. Zinc supplements administered concurrently with cephalexin significantly decreased the peak serum concentration (C(max) ), area under the plasma concentration-time curve from zero to infinity (AUC(0-∞) ) and the time for which the plasma concentration of the drug remained above the minimal inhibitory concentration of the pathogenic organism (T > MIC) of cephalexin [mean percentage decrease (95% confidence intervals) of 31.05% (22.09-40.01%), 27.40% (18.33-36.47%) and 22.33% (12.51-32.16%), respectively; P < 0.05] compared with administration of cephalexin alone. Also, administration of zinc 3h before cephalexin decreased the C(max) , AUC(0-∞) and T > MIC of the drug compared with administration of cephalexin alone [mean percentage decrease (95% confidence intervals) of 11.48% (3.40-19.55%), 18.12% (9.63-26.60%) and 23.75% (14.30-33.20%), respectively; P < 0.05]. In contrast, the pharmacokinetics of cephalexin was not notably altered by administration of zinc 3h after cephalexin dosing (P > 0.05). CONCLUSIONS: The significant interaction between zinc and cephalexin might affect the clinical outcome of cephalexin therapy. The dosing recommendation is that zinc sulfate can be safely administered 3h after a cephalexin dose.

Expression, purification, and improved antigenic specificity of a truncated recombinant bp26 protein of Brucella melitensis M5-90: a potential antigen for differential serodiagnosis of brucellosis in sheep and goats.

Antibodies produced in animals vaccinated using live attenuated vaccines against Brucella spp. are indistinguishable using current conventional serological tests from those produced in infected animals. One potential approach is to develop marker vaccines in which specific genes have been deleted from parental vaccine strains that show good immunogenicity and vaccine efficacy. Corresponding methods of detection for antibodies raised by the marker vaccine should also be developed. A specific fragment of the bp26 gene of Brucella melitensis M5-90 was cloned into vector pQE32 to construct the recombinant plasmid (pQE32-rΔbp26). It was used to transform Escherichia coli M15 (pREP4) host cells, which expressed the rΔbp26 protein. Subsequently, the recombinant protein was purified by immobilized metal affinity chromatography and size-exclusion chromatography. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the purified rΔbp26 protein was represented by only one band, with a molecular weight of 14 kDa, and it showed good antigenic specificity on western blot and enzyme-linked immunosorbent assay (ELISA). The purified rΔbp26 protein was intended to be used as an antigen to develop a novel ELISA to differentiate animals vaccinated with bp26 mutants of Brucella spp. from those infected naturally and those vaccinated with the parental vaccine strains.

Dynamic multiphase semi-crystalline polymers based on thermally reversible pyrazole-urea bonds.

Constructing responsive and adaptive materials by dynamic covalent bonds is an attractive strategy in material design. Here, we present a kind of dynamic covalent polyureas which can be prepared from the highly efficient polyaddition reaction of pyrazoles and diisocyanates at ambient temperature in the absence of a catalyst. Owing to multiphase structural design, poly(pyrazole-ureas) (PPzUs) show excellent mechanical properties and unique crystallization behavior. Besides, the crosslinked PPzUs can be successfully recycled upon heating (~130 °C) and the molecular-level blending of polyurea and polyurethane is realized. Theoretical studies prove that the reversibility of pyrazole-urea bonds (PzUBs) arises from the unique aromatic nature of pyrazole and the N-assisting intramolecular hydrogen transfer process. The PzUBs could further broaden the scope of dynamic covalent bonds and are very promising in the fields of dynamic materials.

Hemorrhagic bulla: a rare presentation of scabies.

Scabies is a contagious skin disorder with multiple presentations, it can also cause nosocomial infection sometimes. Bullous scabies is its rare subtype with male predilection, and typically occurs in the elderly with a median age of 70 years. We herein report a 90-year-old man who was hospitalized in the ward presenting with generalized infection of scabies associated with hemorrhagic bullae on both feet and hands, and leading to a prevalence in the ward. All the lesions including the bullae had excellent response to 10% sulfur ointment alone. No relapse occurred in more than 9 months of follow-up.

Two novel terpenoids from the cultured Perovskia atriplicifolia.

Two new terpenoids, named biperovskatone B (1) and 1α- hydroxyl demethylsalvicanol quinine (2), were isolated from the cultured Perovskia atriplicifolia. Their structures were elucidated by comprehensive analyses of the MS, IR, 1D and 2D NMR spectra. Compound 1 was a novel diterpenoid dimer, containing two different rearranged 9(10 → 20)-abeoabietane type diterpenoid fragments. Compound 2 was a new icetexane diterpenoid with characteristic ortho-quinone carbonyl groups. Both compounds were assayed for their anti-HBV activity in vitro. Results suggested compounds 1 and 2 showed noticeable anti- anti-HBV activity, inhibiting the replication of HBV DNA with IC50 values of 10.78 and 8.61 µM, respectively.

Differential gene expression profiles between two subtypes of ischemic stroke with blood stasis syndromes.

Ischemic stroke is a cerebrovascular thrombotic disease with high morbidity and mortality. Qi deficiency blood stasis (QDBS) and Yin deficiency blood stasis (YDBS) are the two major subtypes of ischemic stroke according to the theories of traditional Chinese medicine. This study was conducted to distinguish these two syndromes at transcriptomics level and explore the underlying mechanisms. Male rats were randomly divided into three groups: sham group, QDBS/MCAO group and YDBS/MCAO group. Morphological changes were assessed after 24 h of reperfusion. Microarray analysis with circulating mRNA was then performed to identify differential gene expression profile, gene ontology and pathway enrichment analyses were carried out to predict the gene function, gene co-expression and pathway networks were constructed to identify the hub biomarkers, which were further validated by western blotting and Tunel staining analysis. Three subsets of dysregulated genes were acquired, including 445 QDBS-specific genes, 490 YDBS-specific genes and 1676 blood stasis common genes. Our work reveals for the first time that T cell receptor, MAPK and apoptosis pathway were identified as the hub pathways based on the pathway networks, while Nfκb1, Egfr and Casp3 were recognized as the hub genes by co-expression networks. This research helps contribute to a clearer understanding of the pathological characteristics of ischemic stroke with QDBS and YDBS syndrome, the proposed biomarkers might provide insight into the accurate diagnose and proper treatment for ischemic stroke with blood stasis syndrome.

Two new biphenyls from the stems of Garcinia tetralata.

Two new biphenyls (1 and 2) and three known xanthones (3-5) were isolated from the ethanol extract of the stems of Garcinia tetralata. Structural elucidations of 1-2 were elucidated by spectroscopic methods including extensive 1D- and 2D-nuclear magnetic resonance spectroscopy techniques. Compounds 1-2 showed anti-rotavirus activities with SI above 10.

Influence of dexmedetomidine on incidence of adverse reactions introduced by hemabate in postpartum hemorrhage during cesarean section.

OBJECTIVE: The purpose of our study was to observe the influence of dexmedetomidine on complications caused by hemabate in patients undergoing caesarean section. METHODS: A total of 120 females (age range, 20-40 years) at 35-40 weeks gestation who delivered by cesarean between September, 2014 and December, 2014 were enrolled in our study. Patients were randomly allocated into three groups that received intravenously physiological saline 20 mL (placebo group), lower dose (0.5 µg kg(-1)) of dexmedetomidine (low-dex gruop) and higher dose (1 µg kg(-1)) of dexmedetomidine (high-dex group) during cesarean section, following the delivery of the infant and intramuscular hemabate injection. RESULTS: Nausea, vomiting, chest congestion and elevated blood pressure were the most common adverse events of placebo group. Compared with placebo group, the above mentioned adverse reactions decreased significantly in both low-dex group and high-dex group (P<0.05), whereas there were no significant difference between low-dex group and high-dex group (P>0.05). As to patient satisfaction score, low-dex group and high-dex group were all higher than placebo group (P<0.05). Furthermore, there were more patients satisfied with high-dex group than low-dex group (P<0.05). CONCLUSION: Dexmedetomidine (0.5 µg kg(-1) and 1 µg kg(-1)) were all effective in preventing adverse reactions introduced by hemabate and improve parturients' satisfaction in patients undergoing cesarean delivery. And higher dose (1 µg kg(-1)) of dexmedetomidine is superior to lower dose (0.5 µg kg(-1)) in patient satisfaction.

The Role of T Helper 17 Cells and Other IL-17-Producing Cells in Bone Resorption and Remodeling.

In recent decades, many studies have highlighted the role of IL-17-producing cells in bone resorption. However, the importance of many IL-17-producing cell types remains largely unknown in bone remodeling. In this review, we summarize the function of IL-17-producing cells, with a focus on T helper 17 (Th17) cells, in bone resorption and remodeling.

Dangerous blind tracheal intubation attempt due to fiberscope non-availability in a pediatric patient with retropharyngeal abscess caused by a large fish bone.

In China, foods containing bones are sometimes fed to young infants. Occasionally, this practice results in bone aspiration and retropharyngeal abscess, a potentially life-threatening infection in the deep space of the neck that can compromise the airway. The main concern in managing patients with retropharyngeal abscess is airway management. In China, not all hospitals and operating rooms are equipped with fiberscopes, particularly pediatric-size fiberscopes. Emergency airway management can be dangerous when a fiberscope is unavailable. We present the case of a 21-month-old baby girl with a retropharyngeal abscess secondary to fish bone ingestion. During an attempted blind tracheal intubation due to fiberscope non-availability, the abscess ruptured, and the pus released from it obstructed the airway. The patient was successfully treated despite the inadequate resources and dangerous complication. We recommend a detailed preoperative airway assessment and preparation for fiberscopic tracheal intubation in such patients to prevent this dangerous complication.

Tandem C-H oxidation/cyclization/rearrangement and its application to asymmetric syntheses of (-)-brussonol and (-)-przewalskine E.

Natural products are a vital source of lead compounds in drug discovery. Development of efficient tandem reactions to build useful compounds and apply them to the synthesis of natural products is not only a significant challenge but also an important goal for chemists. Here we describe a tandem C-H oxidation/cyclization/rearrangement of isochroman-derived allylic silylethers, promoted by DDQ and InCl3. This method allows the efficient construction of tricyclic benzoxa[3.2.1]octanes with a wide substrate scope. We employ this tandem reaction to achieve the asymmetric total syntheses of (-)-brussonol and (-)-przewalskine E.

Safety and efficacy of intra-articular injection of tranexamic acid in total knee arthroplasty.

Tranexamic acid was intra-articularly injected in total knee arthroplasty (TKA) to reduce blood loss and transfusion. However, no single study has been large enough to definitively determine whether it is safe and effective. To determine the safety and efficacy of intra-articular tranexamic acid in TKA, the authors searched various databases for relevant randomized controlled trials. Mean difference (MD) in total blood loss, risk ratio (RR) for transfusion, and complication rate in the tranexamic acid-treated group vs the placebo group were calculated. Seven randomized controlled trials, including 622 patients (174 men and 448 women), were identified. All 7 placebo-controlled randomized trials had a low risk of bias. The pooled results showed a positive effect of tranexamic acid in all treatment groups, with significant reduction in total blood loss (MD, -396.42 mL [95% confidence interval (CI), -629.64 to -163.20]; P=.0009). However, there was significant heterogeneity in the finding (chi-square=27.16, df=3, I(2)=89%; P<.00001) among studies. The pooled results indicated that 5.8% (18 of 309) of tranexamic acid-treated patients required transfusion compared with 27.2% (85 of 313) of placebo-treated patients. This difference was significant (RR, 0.22; 95% CI, 0.14-0.35; P<.00001). There was no significant difference between the groups in the incidence of deep venous thrombosis (RR, 0.83; 95% CI, 0.35-1.98; P=.68) or pulmonary embolism (RR, 0.54; 95% CI, 0.10-2.85; P=.46). In all, intra-articular tranexamic acid significantly reduced total blood loss, drainage, reduction of hemoglobin, and the need for transfusion without increasing the incidence of deep venous thrombosis and pulmonary embolism. Intra-articular tranexamic acid is safe and efficacious in TKA.