166 research outputs found

    Structure and tanning properties of dialdehyde carboxymethyl cellulose: Effect of degree of substitution

    Get PDF
    Content: Developing novel tanning agents from renewable biomass is regarded as an effective strategy for sustainable leather industry. In this study, a series of dialdehyde carboxymethyl cellulose (DCMC) were prepared by periodate oxidation of carboxymethyl cellulose (CMC) with varying degrees of substitution (DS: 0.7, 0.9 and 1.2). The structural properties of DCMC were characterized. Size Exclusive Chromatography measurements showed that CMC underwent severe degradation during periodate oxidation, resulting in the decline of weight-average molecular weight from 250,000 g/mol to around 13,000 g/mol. FT-IR analysis illustrated that aldehyde group was successfully introduced into DCMC. The aldehyde group content of DCMC decreased from 8.38 mmol/g to 2.95 mmol/g as the DS rose from 0.7 to 1.2. Interestingly, formaldehyde was found to be produced in DCMC, and its content was 159.4, 151.7 and 38.4 mg/L, respectively when the DS of CMC was 0.7, 0.9 and 1.2, respectively. Further analysis by HPLC found that fructose was formed during oxidative degradation, and was subsequently oxidized to generate formaldehyde. This was in accordance with the fact that higher DS resulted in lower formaldehyde content in DCMC. The whole reaction mechanism is still under investigation at the moment. Tanning trials showed that the shrinkage temperature and thickening rate of DCMC tanned leather decreased as the DS increased. This should be due to the difference in aldehyde content of DCMC. Leather tanned by DCMC-0.7 (DS of CMC was 0.7) had the highest shrinkage temperature of 81°C and thickening rate of 76%. It was noteworthy that the formaldehyde content in DCMC tanned leather was only 0.11-0.40 mg/kg even though DCMC contained a small amount of formaldehyde. In general, we hope the work on dialdehyde tanning agent derived from CMC could provide some essential data for the development of sustainable tanning material and process. Take-Away: 1. Higher degree of substitution (DS) of CMC resulted in lower aldehyde group content of DCMC. 2. The formaldehyde content of DCMC was negatively correlated with DS. 3. The tanning performance of DCMC with lower DS was better

    catena-Poly[[(acetato-κ2 O,O′)(methanol-κO)cadmium(II)]-μ-[1,2-bis­(1H-benzimid­azol-2-yl)ethane]-κ2 N 3:N 3′-[(acetato-κ2 O,O′)(methanol-κO)cadmium(II)]-di-μ-chlorido]

    Get PDF
    In the title complex, [Cd2(CH3COO)2Cl2(C16H14N4)(CH3OH)2]n, the CdII atom is six-coordinated by one N atom from a centrosymmetric bridging 1,2-bis­(2,2′-1H-benzimidazol-2-yl)ethane (bbe) ligand, two O atoms from a chelating acetate ligand, one O atom from a methanol mol­ecule and two bridging Cl atoms in a distorted octa­hedral geometry. The CdII atoms are connected alternately by the Cl atoms and bbe ligands, leading to a chain along [001]. These chains are further linked by O—H⋯O hydrogen bonds. Intra­chain N—H⋯O hydrogen bonds are observed

    Bis{1-[(1H-benzimidazol-1-yl)methyl-κN 3]-1H-1,2,3,4-tetra­zole}silver(I) nitrate

    Get PDF
    In the title salt, [Ag(C9H8N6)2]NO3, the central AgI atom is linearly coordinated by the N atoms [171.97 (8)°] from two 1-[(benzimidazol-1-yl)meth­yl]-1H-1,2,3,4-tetra­zole ligands. The benzimidazole rings in adjacent mol­ecules are parallel with an average inter­planar distance of 3.461 Å; adjacent mol­ecules are linked through N—H⋯O hydrogen bonds into a linear chain along the b-axis direction

    Acetato­chlorido[2,2′-(ethane-1,2-di­yl)di-1H-benzimidazole]­copper(II) monohydrate

    Get PDF
    In the title complex, [Cu(CH3COO)Cl(C16H14N4)]·H2O, the CuII ion is five-coordinated by two N atoms from a 2,2′-(ethane-1,2-di­yl)di-1H-benzimidazole ligand, two O atoms from a chelating acetate ligand and one terminal monodentate Cl atom in a distorted square-pyramidal geometry. In the crystal, adjacent mol­ecules are linked through O—H⋯Cl, N—H⋯Cl, N—H⋯O and O—H⋯O hydrogen bonds into a three-dimensional network

    Identification of quality markers of Xiaojin Pills using a combination of high-performance liquid chromatographtandem mass spectrometry and multivariate analysis

    Get PDF
    Purpose: To establish an appropriate quality control method for Xiaojin pills using high-performance liquid chromatograph-tandem mass spectrometry combined with multivariate analysis.Methods: High-performance liquid chromatograph-tandem mass spectrometry was established to detect and quantify 13 chemical components of Xiaojin Pills. In order to evaluate the quality difference between diverse specimens of Xiaojin Pills, several multivariate statistical techniques were applied to analyze the dissimilarity between different batches of samples, including principal composition analysis method and clustering methodology.Results: Five chemical components were identified as primary quality markers, which can be used to accurately distinguish various samples and command the quality of Xiaojin Pills.Conclusion: The results afford a professionally scientific basis for the quality monitoring of Xiaojin Pills and also furnishes reasonable ideas and suggestions for the quality control of other traditional drugs.Keywords: Xiaojin Pills, HPLC-MS/MS, Quality control, Chemometrics, Quality marker

    Comparison analysis of PD-1/PD-L1 inhibitors plus lenvatinib or gemcitabine/cisplatin as first-line treatment for patients with advanced intrahepatic cholangiocarcinoma

    Get PDF
    BackgroundIntrahepatic cholangiocarcinoma (ICC) is a highly aggressive primary liver cancer, with increasing incidence worldwide. Effective first-line treatments for advanced ICC patients are currently limited. Therefore, our study aimed to assess the efficacy and safety of programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors in combination with gemcitabine/cisplatin (GC) and lenvatinib as first-line treatment in advanced ICC patients.MethodsThis retrospective cohort study included 51 advanced ICC patients, among whom 25 patients were administered with PD-1/PD-L1 plus lenvatinib and 26 patients were administered with PD-1/PD-L1 plus GC. Baseline characteristics including demographic information, medical history, clinical characteristics, laboratory data, and imaging examination were collected. The primary endpoints were progression-free survival (PFS) and sixth- and ninth-month overall survival (OS) rate. Survival curve was plotted by the Kaplan–Meier method. A Cox proportion risk model was performed to investigate independent risk factors of PFS and OS. The secondary outcomes were objective response rate (ORR), disease control rate (DCR), and adverse events.ResultsThe median age of advanced ICC patients in our study was 58.0 (95% confidence interval [95% CI] = 48.0–72.4) years, with 33 male and 18 female patients. Patients in the PD-1/PD-L1 inhibitors plus lenvatinib group were more likely to be in ECOG grade above 1, develop ascites, and have an elevated level of ALT. The ORR was 16.0% in the PD-1/PD-L1 inhibitors plus lenvatinib group and 23.1% in the GC group (p = 0.777). The DCR was 52.0% in the lenvatinib group and 46.2% in the GC group (p = 0.676). The combination treatment of PD-1/PD-L1 inhibitors plus lenvatinib was associated with longer PFS than the GC group; however, it was not statistically significant (lenvatinib: 9.5 months, GC: 5.1 months, p = 0.454). The sixth-month and ninth-month OS rates were 82.0% and 76.9% in the lenvatinib group and 87.4% and 71.5% in the GC group. After adjusting for confounders, multivariate Cox regression analysis showed that ECOG grade above 1 was an independent risk factor for PFS (hazard ratio [HR] = 3.388, 95% CI = 1.312–8.746, p = 0.012) and OS (HR = 4.220, 95% CI = 1.131–15.742, p = 0.032).ConclusionPD-1/PD-L1 inhibitors in combination with lenvatinib or GC all demonstrated significant efficacy and safety as first-line treatment in patients with advanced ICC. As for patients who refuse or are intolerant to chemotherapy, PD-1/PD-L1 plus lenvatinib would be recommended

    SPECIFIC NEUROPROTECTIVE EFFECTS OF MANUAL STIMULATION OF REAL ACUPOINTS VERSUS NON-ACUPOINTS IN RATS AFTER MIDDLE CEREBRAL ARTERY OCCLUSION

    Get PDF
    The objective of this study was to investigate the effectiveness and specific effects of acupuncture on ischemic-induced damage in rats after permanent middle cerebral artery occlusion. Cerebral ischemia was induced by middle cerebral artery occlusion in male Wistar rats. The rats were divided into the following 4 groups: normal controls, ischemic, real acupuncture-treated (Shuigou, DU26), and non-acupoint-treated groups. On the third postoperative day, neurological deficit scores, cerebral blood flow, infarction volume, and neuronal cell death counts were measured. In the real acupuncture-treated group, the neurological deficit scores and cerebral blood flow were improved (p < 0.05) and the infarction volume and neuronal cell death counts were reduced (p < 0.01) compared to the ischemic and non-acupoint-treated groups. The present study demonstrated that real acupuncture was effective against focal ischemia-induced damage in rats after middle cerebral artery occlusion, and the effects were specifically related to the right needling location

    Redox memristors with volatile threshold switching behavior for neuromorphic computing

    Get PDF
    The spiking neural network (SNN), closely inspired by the human brain, is one of the most powerful platforms to enable highly efficient, low cost, and robust neuromorphic computations in hardware using traditional or emerging electron devices within an integrated system. In the hardware implementation, the building of artificial spiking neurons is fundamental for constructing the whole system. However, with the slowing down of Moore’s Law, the traditional complementary metal-oxide-semiconductor (CMOS) technology is gradually fading and is unable to meet the growing needs of neuromorphic computing. Besides, the existing artificial neuron circuits are complex owing to the limited bio-plausibility of CMOS devices. Memristors with volatile threshold switching (TS) behaviors and rich dynamics are promising candidates to emulate the biological spiking neurons beyond the CMOS technology and build high-efficient neuromorphic systems. Herein, the state-of-the-art about the fundamental knowledge of SNNs is reviewed. Moreover, we review the implementation of TS memristor-based neurons and their systems, and point out the challenges that should be further considered from devices to circuits in the system demonstrations. We hope that this review could provide clues and be helpful for the future development of neuromorphic computing with memristors

    Evaluation of human enterovirus 71 and coxsackievirus A16 specific immunoglobulin M antibodies for diagnosis of hand-foot-and-mouth disease

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Hand-foot-and-mouth disease (HFMD) is caused mainly by the human enterovirus type 71 (HEV71) and the Coxsackievirus A group type 16 (CVA16). Large outbreaks of disease have occurred frequently in the Asia-Pacific region. Reliable methods are needed for diagnosis of HFMD in childen. IgM-capture ELISA, with its notable advantages of convenience and low cost, provides a potentially frontline assay. We aimed to evaluate the newly developed IgM-capture ELISAs for HEV71 and CVA16 in the diagnosis of HFMD, and to measure the kinetics of IgM over the course of HEV71 or CVA16 infections.</p> <p>Results</p> <p>We mapped, for the first time, the kinetics of IgM in HEV71 and CVA16 infection. HEV71- and CVA16-IgM were both detectable in some patients on day 1 of illness, and in 100% of patients by day 5 (HEV71) and day 8 (CVA16) respectively; both IgMs persisted for several weeks. The IgM detection rates were 90.2% (138 of 153 sera) and 68.0% (66 of 97 sera) for HEV71 and CVA16 infections, respectively, during the first 7 days of diseases. During the first 90 days after onset these values were 93.6% (233 of 249 sera) and 72.8% (91 of 125 sera) for HEV71 and CVA16 infections, respectively. Some cross-reactivity was observed between HEV71- and CVA16-IgM ELISAs. HEV71-IgM was positive in 38 of 122 (31.1%) CVA16 infections, 14 of 49 (28.6%) other enteroviral infections and 2 of 105 (1.9%) for other respiratory virus infected sera. Similarly, CVA16-IgM was apparently positive in 58 of 211 (27.5%) HEV71 infections, 16 of 48 (33.3%) other enterovirus infections and 3 of 105 (2.9%) other respiratory virus infected sera. Nevertheless, the ELISA yielded the higher OD<sub>450 </sub>value of main antibody than that of cross-reaction antibody, successfully identifying the enteroviral infection in 96.6% (HEV71) and 91.7% (CVA16) cases. When blood and rectal swabs were collected on the same day, the data showed that the agreement between IgM-capture ELISA and real-time RT-PCR in HEV71 was high (Kappa value = 0.729) while CVA16 somewhat lower (Kappa value = 0.300).</p> <p>Conclusions</p> <p>HEV71- and CVA16-IgM ELISAs can be deployed successfully as a convenient and cost-effective diagnostic tool for HFMD in clinical laboratories.</p
    corecore