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1.
Metal N-heterocyclic carbenes (M-NHCs) on the pore walls of a porous metal-organic framework (MOF) can be used as active sites for efficient organic catalysis. Traditional approaches that need strong alkaline reagents or insoluble Ag2O are not, however, suitable for the incorporation of NHCs on the backbones of MOFs because such reagents could destroy their frameworks or result in low reactivity. Accordingly, development of facile strategies toward functional MOFs with covalently bound M-NHCs for catalysis is needed. Herein, we describe the development of a general and facile approach to preparing MOFs with covalently linked active M-NHC (M = Pd, Ir) single-site catalysts by using a soluble Ag salt AgOC(CF3)3 as the source and subsequent transmetalation. The well-defined M-NHC-MOF (M = Pd, Ir) catalysts obtained in this way have shown excellent catalytic activity and stability in Suzuki reactions and hydrogen transfer reactions. This provides a general and facile strategy for anchoring functional M-NHC single-site catalysts onto functionalized MOFs for different reactions.  相似文献   

2.
Hydrogel optical light-guides have received substantial interest for applications such as deep-tissue biosensors, optogenetic stimulation and photomedicine due to their biocompatibility, (micro)structure control and tissue-like Young''s modulus. However, despite recent developments, large-scale fabrication with a continuous synthetic methodology, which could produce core-sheath hydrogel fibers with the desired optical and mechanical properties suitable for deep-tissue applications, has yet to be achieved. In this study, we report a versatile concept of integrated light-triggered dynamic wet spinning capable of continuously producing core-sheath hydrogel optical fibers with tunable fiber diameters, and mechanical and optical propagation properties. Furthermore, this concept also exhibited versatility for various kinds of core-sheath functional fibers. The wet spinning synthetic procedure and fabrication process were optimized with the rational design of the core/sheath material interface compatibility [core = poly(ethylene glycol diacrylate-co-acrylamide); sheath = Ca-alginate], optical transparency, refractive index and spinning solution viscosity. The resulting hydrogel optical fibers exhibited desirable low optical attenuation (0.18 ± 0.01 dB cm−1 with 650 nm laser light), excellent biocompatibility and tissue-like Young''s modulus (<2.60 MPa). The optical waveguide hydrogel fibers were successfully employed for deep-tissue cancer therapy and brain optogenetic stimulation, confirming that they could serve as an efficient versatile tool for diverse deep-tissue therapy and brain optogenetic applications.  相似文献   

3.
4.
The present study was designed to understand the cigarette smoking-induced alterations in hormones and the resulting changes in platelet serotonin (5-hydroxytryptamine, 5-HT) and monoamine oxidase (MAO-B) activity in chronic smokers. Human male volunteers aged 35 ± 8 years, were divided into two groups, namely controls and smokers (12 ± 2 cigarettes per day for 7–10 years). Results showed that cigarette smoking significantly (p < 0.05) elevated plasma triiodothyronine (T3), cortisol and testosterone levels with significant (p < 0.05) reduction in plasma tryptophan and thyroxin (T4). Moreover, smokers showed reduced platelet 5-HT levels and MAO-B activity. In smokers, plasma cortisol was negatively correlated with tryptophan (r = −0.386), platelet MAO-B (r = −0.264), and 5-HT (r = −0.671), and positively correlated with testosterone (r = 0.428). However, testosterone was negatively correlated with platelet MAO-B (r = −0.315), and 5-HT (r = −.419) in smokers. Further, smokers plasma T3 levels were negatively correlated with platelet MAO-B (r = −0.398), and 5-HT (r = −0.541), whereas T4 levels were positively correlated with platelet MAO-B (r = 0.369), and 5-HT (r = 0.454). In conclusion, our study showed that altered testosterone and cortisol levels may aggravate behavior, mood disturbances and symptoms of depression by decreasing platelet 5-HT and MAO-B activity in smokers.  相似文献   

5.
According to the statistics of the World Health Organization, an estimated 17.9 million people die from cardiovascular diseases each year, representing 31% of all global deaths. Continuous non-invasive arterial pressure (CNAP) is essential for the management of cardiovascular diseases. However, it is difficult to achieve long-term CNAP monitoring with the daily use of current devices due to irritation of the skin as well as the lack of motion artifacts suppression. Here, we report a high-performance skin-like optoelectronic system integrated with ultra-thin flexible circuits to monitor CNAP. We introduce a theoretical model via the virtual work principle for predicting the precise blood pressure and suppressing motion artifacts, and propose optical difference in the frequency domain for stable optical measurements in terms of skin-like devices. We compare the results with the blood pressure acquired by invasive (intra-arterial) blood pressure monitoring for >1500 min in total on 44 subjects in an intensive care unit. The maximum absolute errors of diastolic and systolic blood pressure were ±7/±10 mm Hg, respectively, in immobilized, and ±10/±14 mm Hg, respectively, in walking scenarios. These strategies provide advanced blood pressure monitoring techniques, which would directly address an unmet clinical need or daily use for a highly vulnerable population.  相似文献   

6.
Prostate carcinoma is the most frequently diagnosed malignancy and the second leading cause of death as a result of cancer in men in the US and other parts of the world. There are conflicting reports on the serum levels of testosterone and 17β-estradiol (E2) in benign prostatic hyperplasia (BPH) and prostate cancer. This study was designed to evaluate the serum concentrations of these hormones in patients with these disorders. Serum levels of prostate specific antigen (PSA), total testosterone and estradiol were determined in 228 subjects comprising of 116 subjects with BPH, 62 subjects with prostate cancer (CaP) and 50 age-matched apparently healthy controls, using ELISA methods. PSA levels were significantly elevated (p < 0.05) in BPH subjects than controls, while there was no significant difference (p > 0.05) in testosterone and estradiol levels of these subjects. PSA and estradiol levels were significantly higher (p < 0.05) in CaP subjects than in controls, while there was no observed significant difference (p > 0.05) in testosterone levels. CaP subjects had significantly raised PSA, testosterone, and estradiol levels than BPH subjects. The mean molar ratio of testosterone: E2 was lowest among CaP patients (134:1) and highest among controls (166:1). Significant positive correlation between PSA and 17β-estradiol was observed in prostate disorders (BPH and CaP patients: r = 0.347; p = 0.000). Significant negative correlations between testosterone and PSA were also observed among BPH patients (r = −0.221, p = 0.049) and control subjects (r = −0.490, p = 0.000). No significant correlation existed between testosterone and PSA in CaP patients (r = 0.051, p = 0.693). Correlations between age and estradiol in both BPH and CaP were not significant (p > 0.05). This study has shown that, there was a significant increase in serum estradiol in CaP subjects, while the testosterone levels in both BPH and CaP subjects were not different from those of controls.  相似文献   

7.
Retrieving historical fine particulate matter (PM2.5) data is key for evaluating the long-term impacts of PM2.5 on the environment, human health and climate change. Satellite-based aerosol optical depth has been used to estimate PM2.5, but estimations have largely been undermined by massive missing values, low sampling frequency and weak predictive capability. Here, using a novel feature engineering approach to incorporate spatial effects from meteorological data, we developed a robust LightGBM model that predicts PM2.5 at an unprecedented predictive capacity on hourly (R= 0.75), daily (R= 0.84), monthly (R= 0.88) and annual (R= 0.87) timescales. By taking advantage of spatial features, our model can also construct hourly gridded networks of PM2.5. This capability would be further enhanced if meteorological observations from regional stations were incorporated. Our results show that this model has great potential in reconstructing historical PM2.5 datasets and real-time gridded networks at high spatial-temporal resolutions. The resulting datasets can be assimilated into models to produce long-term re-analysis that incorporates interactions between aerosols and physical processes.  相似文献   

8.
Abdominal obesity (AO) and metabolic syndrome (MetS) are associated with the cardiovascular disease and type 2 diabetes. Serum uric acid (SUA) is often elevated in subjects with the AO. We aimed to investigate the association of elevated SUA with the components of MetS, oxidative stress and TG/HDL-C ratio in AO subjects. This cross-sectional study used data from a Health Survey for Prevention of Hypertension and Type 2 Diabetes Mellitus in residents of two districts in Phitsanulok province, including 443 subjects. Anthropometric, blood pressure (BP) and biochemical variables were measured. We categorized the participants to two-group as 248 AO subjects (median age = 58, interquartile range 50.0–65.0 years) and 195 non-AO subjects (median age = 53, interquartile range 47.0–62.0 years). Waist circumference was significantly correlated with SystBP, DiastBP, Glu and SUA (P < 0.05) and SUA was significantly correlated with Glu, TG, HDL-C and TG/HDL-C ratio (P < 0.05). By using multiple logistic regression, we found the association of elevated SUA with abdominal obesity, hyperglycemia, hypertriglyceridemia, reduced HDL-C, elevated TG/HDL-C ratio, MetS and increased oxidative stress after adjusting for their covariates. Our study demonstrated that circulating UA is a major antioxidant and might help protect against free-radical oxidative damage. However, elevated SUA concentrations associated with oxidative stress, MetS, insulin resistance, and components of MetS. Then, SUA may be a marker of increased oxidative stress, insulin resistance and MetS, implying an increased risk of vascular disease and T2DM.  相似文献   

9.
Vitamin D deficiency is highly prevalent in Indian children of northern, western and southern states. Serum 25 hydroxy cholecalferol (ng/ml) was analyzed in 310 children and adolescents of pediatric hospital of Kolkata, India. Serum calcium (mg/dl), phosphorous (mg/dl) and alkaline phosphatase (IU/L) data was obtained. Median 25(OH)D was 19 ng/ml. 19.2 % of population had serum 25(OH)D < 10 ng/ml (severe deficiency), 52.9 % had <20 ng/ml (deficiency), 24.5 % had 20–29 ng/ml (insufficiency) and 22.6 % had >30 ng/ml (optimum). Deficiency was highest in adolescents (86.1 %), followed by school children (61.0 %), lowest in pre-school children (41.6 %). 25(OH)D concentrations was lowest in winters (P = 0.002) and spring (P = 0.03) compared to summer. There was no correlation with calcium (P = 0.99), phosphorous (P = 0.23) and ALP (P = 0.63). There is high prevalence of vitamin D deficiency in children and adolescents of eastern India. Prevalence was lower in younger subjects. 25(OH)D did not correlate with bone mineral markers.  相似文献   

10.
The present study was aimed at assessing alterations in serum PCT in terms of its relation to body weight gain in pulmonary tuberculosis (PTB) patients undergoing treatment. Among patients (25–75 years) diagnosed with pulmonary tuberculosis, those that were new smear positive, showed sputum conversion at the end of 2 months and were declared clinically cured at the end of 6 months, were included in the study (n = 40). Serum procalcitonin was determined by BRAHMS PCT-Q kit. Patients were divided into two study groups—Group 1 (n = 21; serum PCT > 2 ng/ml at diagnosis), Group 2 (n = 19; serum PCT > 10 ng/ml at diagnosis). Body weights of all patients were obtained at three different time points, PTB-0 (at diagnosis), PTB-2 (after 2 months of intensive treatment) and PTB-6 (after 6 months of treatment). In both groups, mean body weights at PTB-2 and PTB-6 were significantly higher than those at PTB-0 and at PTB-6 were significantly higher than those at PTB-2. However, percentage body weight gain following 2 months of intensive treatment was higher in group 1 (4.05 % gain, p < 0.01) than in group 2 (2.75 % body weight gain, p < 0.05). Thus, the percentage gain in group 1 was tending more towards the desirable minimum gain of 5 % during intensive phase. Increase in serum PCT levels in pulmonary tuberculosis is inversely associated with body weight gain during treatment. Thus, PCT could play a role in regulation of body weight gain in anorectic conditions like tuberculosis.  相似文献   

11.
Metabolic syndrome (MetS) is a cluster of interrelated common clinical disorders. The role of resistin in insulin sensitivity and MetS is controversial till date. So, the aim of the present study was to investigate the relationship of plasma resistin levels with markers of the MetS in Indian subjects. In a case control study, total 528 subjects were selected for the study. 265 (194 male and 71 female) were cases (with MetS) and 263 (164 male and 99 female) were controls (without MetS). Required anthropometric measurements and calculations were carried out accordingly. All the Biochemical estimations were carried out according to standard protocol. Resistin level was measured by the standard protocol (By ELISA i.e. enzyme linked immunosorbent assay) as illustrated in the kit. Insulin level was also measured by the standard protocol as illustrated in the kit and insulin resistance was calculated by the standard procedures. Plasma resistin levels were significantly higher in cases compared with controls (male = 13.05 ± 4.31 vs. 7.04 ± 2.09 ng/ml; p ≤ 0.001 and female = 13.53 ± 4.14 vs. 7.42 ± 2.30 ng/ml; p ≤ 0.001). Plasma resistin levels were well correlated with waist circumference, glucose, triglycerides, waist/hip ratio, systolic and diastolic blood pressure, high density lipoprotein, total cholesterol, serum low density lipoprotein, serum very low density lipoprotein, insulin and insulin resistance. Plasma resistin levels were elevated in presence of the MetS and were associated with increased metabolic risk factors.  相似文献   

12.
The plasmonic response of gold clusters with atom number (N) = 100–70 000 was investigated using scanning transmission electron microscopy-electron energy loss spectroscopy. For decreasing N, the bulk plasmon remains unchanged above = 887 but then disappears, while the surface plasmon firstly redshifts from 2.4 to 2.3 eV above = 887 before blueshifting towards 2.6 eV down to = 300, and finally splitting into three fine features. The surface plasmon''s excitation ratio is found to follow N0.669, which is essentially R2. An atomically precise evolution picture of plasmon physics is thus demonstrated according to three regimes: classical plasmon (= 887–70 000), quantum confinement corrected plasmon (= 300–887) and molecule related plasmon (< 300).  相似文献   

13.
Psoriasis is a chronic inflammatory disease associated with an increased insulin resistance, obesity and cardiovascular risk. The present study was aimed to assess insulin resistance and pattern of body fat deposition in psoriasis. Body mass index (BMI) and waist circumference (WC) were measured in 40 psoriatic patients and 46 age- and sex-matched control subjects. Fasting blood glucose (FBG) and serum insulin level were measured by standard photometric method and ELISA respectively. HOMA-IR (homeostatic model of insulin resistance) was calculated by appropriate software. The results indicated that case and control groups were comparable in terms of age and sex (p = 0.934) with an increased prevalence of psoriasis among male subjects (60 %). FBG and mean WC between the two groups were statistically not significant (p value = 0.271 and 0.21 respectively). BMI was significantly higher in case group compared to the control group (p = 0.049). Serum insulin level and insulin resistance in the psoriatic patients were significantly higher (p value <0.001). Multiple regression analysis revealed that insulin resistance (measured by HOMA) was dependent on BMI and WC at a significance level of p < 0.001 and 0.043 respectively. Therefore, the psoriatic patients in this region have significantly high amount of fasting serum insulin level along with an increased IR though their FBG level remains normal. Furthermore, these abnormalities are significantly dependent on total body fat as well as abdominal fat deposits. We suggest that psoriatic patients need to be evaluated for metabolic syndrome and managed accordingly.  相似文献   

14.
Despite ample sunshine, 50–90% Indian children have Vitamin D deficiency (VDD). This enigma of widespread VDD needs exploration especially among under-fives as physiological variations in Vitamin D Binding Protein (VDBP) levels could be potential confounders in the interpretation of total 25-hydroxyvitamin D [25(OH)D]. However, there is scarce information about relevance of VDBP levels in under-five age group. We therefore, explored association of VDBP levels among 1–5 year old children with VDD. Serum levels of 25(OH)D, VDBP, calcium, parathyroid hormone (PTH) and alkaline phosphatase were estimated in 210 apparently healthy children in the age group of 1–5 years. VDD was defined as serum 25(OH)D levels < 20 ng/ml as per the IOM classification. VDBP levels were classified as low if levels were < 168 μg/ml as per the kit. The prevalence of VDD was 79.5% (n = 167) and VDBP levels were low in 48.6% (n = 102) of children. 25(OH)D levels correlated positively with VDBP (r = 0.298, p = 0.0001). A significant number of children (52.7%) with VDD had low VDBP (p = 0.015). and despite adequate sun exposure, 43% of children showed VDD and 56.6% had low VDPB levels. The low VDBP levels largely explain low 25OHD levels without necessarily implying VDD. It may add a new dimension for better understanding of widespread VDD among under-five children. It thus, points towards the need for redefining cut offs and complete evaluation of vitamin D status among under-fives including VDBP.  相似文献   

15.
Elastomers are essential for stretchable electronics, which have become more and more important in bio-integrated devices. To ensure high compliance with the application environment, elastomers are expected to resist, and even self-repair, mechanical damage, while being friendly to the human body. Herein, inspired by peptidoglycan, we designed the first room-temperature autonomous self-healing biodegradable and biocompatible elastomers, poly(sebacoyl 1,6-hexamethylenedicarbamate diglyceride) (PSeHCD) elastomers. The unique structure including alternating ester-urethane moieties and bionic hybrid crosslinking endowed PSeHCD elastomers superior properties including ultrafast self-healing, tunable biomimetic mechanical properties, facile reprocessability, as well as good biocompatibility and biodegradability. The potential of the PSeHCD elastomers was demonstrated as a super-fast self-healing stretchable conductor (21 s) and motion sensor (2 min). This work provides a new design and synthetic principle of elastomers for applications in bio-integrated electronics.  相似文献   

16.
Most metal–organic frameworks (MOFs) hardly maintain their physical and chemical properties after exposure to alkaline aqueous solutions, thus precluding their use as potential electrode materials for electrochemical energy storage devices. Here, we present the design and synthesis of a highly alkaline-stable metal oxide@MOF composite, Co3O4 nanocube@Co-MOF (Co3O4@Co-MOF), via a controllable and facile one-pot hydrothermal method under highly alkaline conditions. The obtained composite possesses exceptional alkaline stability, retaining its original structure in 3.0 M KOH for at least 15 days. Benefitting from the exceptional alkaline stability, unique structure, and larger surface area, the Co3O4@Co-MOF composite shows a specific capacitance as high as 1020 F g−1 at 0.5 A  g−1 and a high cycling stability with only 3.3% decay after 5000 cycles at 5 A g−1. The as-constructed solid-state flexible device exhibits a maximum energy density of 21.6 mWh cm−3.  相似文献   

17.
The present work was aimed to study the association of one carbon genetic variants, hyperhomocysteinemia and oxidative stress markers, i.e., serum nitrite, plasma malondialdehyde (MDA) and glutathione (GSH) on intimal medial thickening (IMT) in patients with type 2 diabetes mellitus (T2D). A total number of 76 subjects from ACS Medical College and Hospital, Chennai, India were included in the study, i.e., Group I (n = 42) of T2D and Group II (n = 34) of age- and sex matched healthy controls. The glycated haemoglobin was measured by ion-exchange resin method; plasma homocysteine by Enzyme Linked Immunosorbant Assay method; serum nitrite (nitric oxide, NO), plasma MDA and GSH by spectrophotometric methods; the IMT by high frequency ultrasound. The polymorphisms of one carbon genetic variants were genotyped using polymerase chain reaction-restriction fragment length polymorphism and amplified fragment length polymorphism methods. Results indicate that methyltetrahydrofolate homocysteine methyl transferase (MTR) A2756G allele was found to be protective in T2D and the other variants were not significantly associated with T2D. Glutamate carboxypeptidase II (GCP II) C1561T (r = 0.34; p = 0.05) and methylene tetrahydrofolate reductase (MTHFR) C677T (r = 0.35; 0.04) showed positive correlation with plasma homocysteine in T2D cases. In this study, MTR A2756G allele was found to be protective in T2D; GCP II C1561T and MTHFR C677T showed positive association with plasma homocysteine in T2D cases. Among all the genetic variants, MTR A2756G was found influence IMT. RFC 1 G80A and TYMS 5′-UTR 2R3R showed synergistically interact with MTR A2756G in influencing increase in IMT.  相似文献   

18.
Increase in urine albumin excretion rate (AER) precede a fall in glomerular filtration rate in patients developing diabetic chronic kidney disease (CKD). Our results have shown that 7 (50 %) of diabetic and hypertensive individuals with decreased GFR do not have increased AER. In this cross-sectional study, we measured AER of 75 patients with type 2 diabetes and hypertension by immunoturbidimetric method. We correlated the results with eGFR values obtained by Cockcroft–Gault and MDRD method. The method used was not a compensated method. We measured serum creatinine by modified Jaffe’s kinetic method in autoanalyzer XL-600. Analysis of data showed positive correlation between eGFR and microalbuminuria by both the methods with eGFR <60 mL/min/1.73 m2. Pearson’s correlation co-efficient (r) was 0.9 (p = 0.0001) by Cockcroft–Gault formula and 0.69 (p = 0.0063) by MDRD formula. Our results concluded that there was positive correlation between AER and eGFR <60 mL/min/1.73 m2. We have recognized that these two parameters provide a complimentary benefit in management of cases with CKD.  相似文献   

19.
Ovarian cancer has been emerged as a most common and lethal gynecological malignancy in India. High serum insulin and low adiponectin have been associated with increased risk of ovarian cancer. But their role in development of ovarian cancer is conflicting and little evidence is available. We aimed to evaluate blood levels of insulin and adiponectin in epithelial ovarian cancer (EOC) patients and their association with the risk to develop EOC. The study included following three groups; Group 1: fifty cases of cytohistopathologically confirmed cases of EOC, Group 2: fifty age matched cases of benign ovarian conditions and Group 3: fifty ages matched healthy controls with no evidence of any benign or malignant ovarian pathology as ruled out by clinical examination and relevant investigations. Cytohistopathologically confirmed and newly diagnosed cases of EOC and benign ovarian cancer were included in this study. The median value of fasting serum insulin was significantly high (15.0 µlU/ml, P = 0.02) and adiponectin were significantly low (5.1 µg/ml, P < 0.001) in ovarian cancer patients compared to benign ovarian tumors and healthy controls group. A significant increase risk of ovarian cancer was found in high tertile (≥ 18.7 µlU/ml) of serum insulin level (OR = 2.7; 95% CI = 1.00–6.67, P = 0.04) and lower tertile (≤ 5.45 µg/ml) of adiponectin level (OR = 3.2; 95% CI = 1.10–9.71, P = 0.03). High serum insulin level and low adiponectin levels were significantly associated with increased risk for development of ovarian cancer.  相似文献   

20.
The scalable and high-efficiency production of 2D materials is a prerequisite to their commercial use. Currently, only graphene and graphene oxide can be produced on a ton scale, and the inability to produce other 2D materials on such a large scale hinders their technological applications. Here we report a grinding exfoliation method that uses micro-particles as force intermediates to resolve applied compressive forces into a multitude of small shear forces, inducing the highly efficient exfoliation of layer materials. The method, referred to as intermediate-assisted grinding exfoliation (iMAGE), can be used for the large-scale production of many 2D materials. As an example, we have exfoliated bulk h-BN into 2D h-BN with large flake sizes, high quality and structural integrity, with a high exfoliation yield of 67%, a high production rate of 0.3 g h−1 and a low energy consumption of 3.01 × 106 J g−1. The production rate and energy consumption are one to two orders of magnitude better than previous results. Besides h-BN, this iMAGE technology has been used to exfoliate various layer materials such as graphite, black phosphorus, transition metal dichalcogenides, and metal oxides, proving its universality. Molybdenite concentrate, a natural low-cost and abundant mineral, was used as a demo for the large-scale exfoliation production of 2D MoS2 flakes. Our work indicates the huge potential of the iMAGE method to produce large amounts of various 2D materials, which paves the way for their commercial application.  相似文献   

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