Effect of Br content on phase stability and performance of H2N=CHNH2Pb(I1-x Br x )3 perovskite thin films.

Pristine and Br-doped H2N = CHNH2Pb(I1-x Br x )3 (FAPb(I1-x Br x )3, Br content x = 0, 0.05, 0.15, 0.2, 0.3, and 0.4) films were prepared. The effect of Br-doping on phase stability, defect density, and performance of FAPb(I1-x Br x )3 was investigated by x-ray diffraction (XRD), scanning electron microscopy, ultraviolet-visible-near infrared absorbance spectroscopy, x-ray photoemission spectroscopy (XPS), Kelvin probe force microscopy (KPFM), positron annihilation spectroscopy, and current density-voltage (J-V) characteristics. The XRD measurements exhibit the enhancement of perovskite phase stability at x = 0.05. However, the phase stability decreases gradually with Br content (x) over 0.05. The increase of Br-doping content leads to the downshifting of both valence band (VB) position (indicated by XPS) and Fermi level (illustrated by KPFM). The energy level shifts are most probably due to the increase of Br 4p orbital content in VB and the change of self-doping levels. Doppler broadening spectra of positron annihilation radiation of the samples reveal that, the defect densities of Br-doped samples are much lower than that of pristine FAPbI3. For FAPb(I0.95Br0.05)3 sample, a high photoelectric conversion efficiency of 17.12% (25.7% higher than that of undoped sample) is successfully achieved. The significant enhancement of photoelectric conversion efficiency realized by Br-doping is attributed to the improvement of morphology, high phase stability, and low defect densities.

Improvement of a Model of Brain Death for Transplant-Associated Studies in Rats.

BACKGROUND: The most common method of inducing brain death in rats is inflating an intracranially placed balloon of a Fogarty catheter inserted through a burr hole. However, because of the poor controllability of balloon position, the standardization and stability of the model are compromised. This study examined an improved technique in which the balloon is placed and fixed through double holes. METHODS: Forty adult male Sprague-Dawley (SD) rats were randomly and equally assigned into the single-hole (SH) group and the double-hole (DH) group. In each rat in the DH group, 2 holes were made, at the left frontal bone and parietal bone. A Fogarty catheter was inserted outside of the dura mater through the frontal hole, and its tip was guided out through the parietal hole using an arc-shaped needle. The SH group served as a control. In both groups, normal saline was injected into the balloon at 40 µL/minute until breathing stopped. Mechanical ventilation was instituted immediately and provided for another 6 hours after the determination of brain death. RESULTS: Typical blood pressure patterns were observed in both groups during the brain death induction period, whereas the fluctuation seemed relatively mild in the DH group. Stable brain death with normotension for 6 hours was induced successfully in 18 rats (90%) in the DH group and in 9 rats (45%) in the SH group (P = .002). The mean arterial pressure at 3 hours and thereafter was significantly higher in the DH group compared to the SH group (P < .05). CONCLUSIONS: Our results demonstrate that the DH method is a simple and effective technique to make the brain death model more stable and standardized, possibly due to precise control of the direction of the cannulation and the position of the balloon.

Microencapsulated islet transplantation alleviates podocyte injury in diabetic nephropathy via inhibiting Notch-1 signaling.

OBJECTIVE: Podocyte injury has a critical role in the pathogenesis of diabetic nephropathy (DN). Microencapsulated islet transplantation (MIT) is identified as an effective method for improving the clinical condition of DN. This study aimed to explore the role and mechanism of MIT in alleviating podocyte injury in DN. METHODS: A mouse model of DN was constructed using streptozotocin (STZ). Mice were divided into 3 groups: the untreated diabetic nephropathy group (DN group), the microencapsulated islet transplantation-treated group (MIT group) and the control group. The mice were raised for 6 weeks posterior to islet transplantation to identify the role of MIT. Renal function and structure of glomerular filtration barrier were assessed by urine analysis, histopathological examination, and transmission electron microscopy. The expression levels of several proteins including Caspase-3, Bcl2/Bax, ß-galactosidase, Ki-67, synaptopodin, WT-1, Jagged-1, Notch-1, and Hes-1 in renal tissues were identified via immunohistochemistry (IHC), immunofluorescence (IF), and western blotting techniques. RESULTS: Compared with the DN group, the MIT group presented decreased levels of blood glucose, urinary albumin/creatinine, urea nitrogen, and serum creatinine while their body weight gradually increased. Glomerular injury in the MIT group was significantly better than that in the DN group. The MIT group indicated significantly decreased expression of Caspase-3, ß-galactosidase, Bax/Bcl-2, and Ki-67 when compared with DN group, while the proportion of synaptopodin- and WT-1-positive cells was significantly increased (P < 0.05). The protein expression of Jagged-1, Notch-1, and Hes-1 in the glomerulus of the MIT group was significantly lower than that in the DN group (P < 0.05). CONCLUSION: MIT alleviates podocyte injury induced by DN by inhibiting Notch-1 signaling. The identification of signaling pathways influencing podocyte restoration can help evaluate personalized medicine efficacy for patients treated with islet transplantation.

Measurement of the transition frequency from 2S1/2, F = 0 to 2P1/2, F = 1 states in Muonium.

Muons are puzzling physicists since their discovery when they were first thought to be the meson predicted by Yukawa to mediate the strong force. The recent result at Fermilab on the muon g-2 anomaly puts the muonic sector once more under the spotlight and calls for further measurements with this particle. Here, we present the results of the measurement of the 2S1/2, F = 0 → 2P1/2, F = 1 transition in Muonium. The measured value of 580.6(6.8) MHz is in agreement with the theoretical calculations. A value of the Lamb shift of 1045.5(6.8) MHz is extracted, compatible with previous experiments. We also determine the 2S hyperfine splitting in Muonium to be 559.6(7.2) MHz. The measured transition being isolated from the other hyperfine levels holds the promise to provide an improved determination of the Muonium Lamb shift at a level where bound state QED recoil corrections not accessible in hydrogen could be tested. This result would be sensitive to new physics in the muonic sector, e.g., to new bosons which might provide an explanation of the g-2 muon anomaly and allow to test Lorentz and CPT violation. We also present the observation of Muonium in the n = 3 excited state opening up the possibility of additional precise microwave measurements.

Early mobilization intervention for patient rehabilitation after renal transplantation.

OBJECTIVE: To explore the effectiveness of early mobilization intervention on the rehabilitation of patients after renal transplantation. METHODS: Seventy renal transplant patients treated in our hospital were designated as the control group (n=35, conventional perioperative management) and the intervention group ((n=35, early mobilization intervention based on the concept of fast track surgery (FTS)). Clinical indicators (duration of indwelling drainage tube/urethral catheter, time to first ambulation and hospital stay), gastrointestinal function indicators (time to return of bowel sound, flatus and defecation postoperatively), complications (postoperative incision infection, bleeding, abdominal distension and lung infection) and activities of daily living (ADL) were compared between the two groups. RESULTS: Shorter duration of indwelling drainage tube/catheter, and earlier ambulation and shorter hospital stay were observed in the intervention group than in the control group. The times to return of bowel sound, flatus and defecation were all advanced, and patient satisfaction was increased in the intervention group as well (all P<0.05). Two months after discharge, the scores of ADL in both groups were lower than those before intervention, and those in the intervention group were lower than those in the control group (all P<0.05). CONCLUSION: FTS-based early mobilization intervention greatly promotes postoperative recovery of patients and improves their ADL.

C-peptide and islet transplantation improve glomerular filtration barrier in diabetic nephropathy rats.

OBJECTIVES: Islet transplantation has been proved to be effective in delaying early stage of DN. This study was established to observe the mechanism of islet transplantation on early diabetic nephropathy (DN). METHOD: The diabetes mellitus (DM) rat model was established by an injection of a single-dose streptozotocin. According to the treatment, the rats were randomly divided into 4 groups: the untreated DN rats (DN group); the C-peptide treated rats (CP group); the islet transplanted rats (IT group); the normal control rats (NC group). Renal function and structure of glomerular filtration barrier (GFB) were evaluated by urinalysis and histopathological examination, respectively. The renal fibrotic factors, TGF- ß1 and CTGF, as well as the anti-renal fibrosis factor HGF were assessed by immunohistochemical staining and western blotting methods. RESULTS: After C-peptide treatment and islet transplantation, the GFB structure was obviously improved. The blood glucose significantly decreased in the IT group. The 24h urine protein and glomerular basement membrane thickness decreased, the pathological changes of podocytes improved, TGF- ß1 and CTGF decreased and HGF increased in the CP group and the IT group compared with that in the DN group (P < 0.05), especially in the IT group. CONCLUSION: Islet transplantation could ameliorate the structure of GFB of early DN in a rat model, and the treatment effect was partly attributed to the restoration of C-peptide concentration. Suppressing the fibrosis system can be the potential mechanism of islet transplantation, which is independent of blood glucose control.

A fast SSP-PCR method for genotyping the ATP-binding cassette subfamily B member 1 gene C3435T and G2677T polymorphisms in Chinese transplant recipients.

AIM: P-glycoprotein, the product of the ATP-binding cassette subfamily B member 1 (ABCB1) gene (or the so-called multidrug resistance 1 gene), is an ATP-driven efflux pump contributing to the pharmacokinetics as well as the pharmacokinetics of drugs that are P-glycoprotein substrates, such as tacrolimus. This paper describes the development of a new method for detection of the 3435C/T and 2677G/T/A single nucleotide polymorphisms of the ABCB1 gene. The method is a simple sequence-specific primer polymerase chain reaction (SSP-PCR). METHODS: 158 Chinese health checkup examinees and 214 transplant recipients were included in the study. Genomic DNA was extracted from peripheral blood and amplified with SSP-PCR to detect the 3435C/T and 2677G/T/A mutations in ABCB1. The SSP-PCR condition was optimized, and the PCR results were compared with those of DNA sequencing. RESULTS: In the optimized condition, the two polymorphisms could be clearly distinguished after one-step PCR and electrophoresis. The ABCB1 3435C/T and 2677G/T/A genotypes of the subjects were scanned, and allele-specific bands were successfully amplified by SSP-PCR, which were in full accordance with the results of sequencing. CONCLUSION: As a fast, simple and inexpensive genotyping tool, the method would be practicable in large clinical studies on interindividual pharmacokinetics.

Phytoecdysteroids from Ajuga iva act as potential antidiabetic agent against alloxan-induced diabetic male albino rats.

The present study investigated the protective effect of phytoecdysteroids extracted from the Ajuga iva plant on body weight changes, blood glucose, insulin total protein, blood urea nitrogen (BUN), creatinine, triglycerides (TG), cholesterol, lipid peroxidation, antioxidant enzymes, pancreatic histopathology and hexokinase-I expression in the alloxan-induced diabetic rats. Experimental diabetes was induced following 15day intraperitoneal administration of alloxan. The rats were divided into four groups. Group I served as a sham group, and group II served as the diabetic control. Group III served as a treatment for phytoecdysteroids (10mg/kg), and group IV served as a treatment for phytoecdysteroids (20mg/kg). Phytoecdysteroids restored body weight loss to its antihyperglycemic effect. Blood glucose was reduced 19.2 and 52.9% in group III and IV respectively. Blood insulin (54.9 and 105.88%) and total protein (25 and 72.2%) was increased in group III and IV respectively. BUN, creatinine, TG, cholesterol and lipid peroxidation was significantly reduced following treatment. Catalase, superoxide dismutase (SOD), and glutathione peroxidase activity were significantly increased following treatment. Islet ß-cells are lost in alloxan-induced diabetic rats. Regeneration of islets and reduced atrophy of acinar cells were noted. The number of insulin-secreting cells was tremendously reduced in alloxan-induced diabetic rats. Insulin-secreting cells were increased 48 and 61% in group III and IV respectively. Hexokinase-I mRNA (28.3 & 93.5%) and protein (27.9 and 55.3%) expression were significantly increased following treatment. Taking all these data together, it is suggested that the phytoecdysteroid could be a potential therapeutic agent against experimental diabetes.

Novel Perovskite Solar Cell Architecture Featuring Efficient Light Capture and Ultrafast Carrier Extraction.

A new perovskite solar cell (PSC) structure with a functionalized interface between perovskite and a hole transport material has been proposed in this report. The short circuit current density of PSC was notably enhanced with the novel architecture (with an increase of 8.7%), and a power conversion efficiency (PCE) of 16.93% was achieved. With the increased perovskite/hole conductor interface, hysteresis suppression was observed. The advantages of this structure in light-harvesting efficiency, trap density, and carrier separation rate were proved by various characterization and analysis studies. It is noteworthy that a PCE of 14.67% was achieved with poly(3-hexyl-thiophene), which to our knowledge is the highest performing PSC based on this material.

Glutathione S-transferases T1 null genotype is associated with susceptibility to aristolochic acid nephropathy.

OBJECTIVES: This study aims to determine whether six polymorphisms of the genes involved in drug metabolism are associated with susceptibility to the development and progression of aristolochic acid nephropathy (AAN). METHODS: In the study, 91 aristolochic acid nephropathy (AAN) cases and 152 healthy controls of Chinese Han population were examined. Six common polymorphisms of genes, including multidrug resistance gene 1 (MDR1), cytochrome P450 (CYP1A1), NAD(P)H quinone oxidoreductase 1 (NQO1), glutathione S-transferase (GST) T1 and M1, were determined. Associations between their genotypes with AAN risk were calculated using an unconditional logistic regression model. RESULTS: Among the six candidate polymorphisms, only the distribution frequency of GSTT1 null genotype was significantly higher among AAN cases compared with controls (P = 0.041, 62.6% vs. 48.7%) and was associated with a 1.7-fold increased risk (OR = 1.728, 95%CI: 1.013-2.948, P = 0.045) of developing AAN, after adjustment for age and gender. The stratified analysis further showed that the GSTT1 null genotype was dominant in slow progressive AAN patients (OR = 2.497, 95%CI: 1.028-6.064, P = 0.043). The GSTM1 genotypes were not shown to influence the development of AAN. CONCLUSION: This study supports the hypothesis that polymorphisms related to drug metabolism such as GSTT1 may be an important factor influencing the development of AAN in the Chinese Han population exposed to AA.

[Establishment and preliminary application of polymerase chain reaction with confronting two-pair primers for the single nucleotide polymorphisms of metabolic enzymes].

OBJECTIVE: To develop a simple, accurate, rapid, economic, large-scale detection method for the detection of single nucleotide polymorphisms (SNPs) metabolic enzymes, using polymerase chain reaction with confronting two-pair primers (PCR-CTPP). METHODS: The primers of CYP1A1 (A4889G), EPHX1 (A416G) and NQO1 (C609T) were designed for PCR-CTPP, and the PCR conditions were optimized. The results of genotyping were verified by DNA sequencing. The above SNPs were detected by the PCR-CTPP detection method in a randomly selected 183 healthy individuals of Han ethnicity. The genotype frequencies were analyzed and compared with people from other ethnicities. RESULTS: The allele-specific bands of CYP1A1 (A4889G), EPHX1 (A416G) and NQO1 (C609T) were successfully amplified by PCR-CTPP under the optimal conditions and the results of genotyping were consistent with DNA sequencing. Among 183 healthy Han individuals, the genotypic distributions of CYP1A1 (A4889G) , EPHX1 (A416G) and NQO1 (C609T) showed that the wild-type, homozygous variants, and heterozygotes were 103 (56.3%), 8 (4.4%), 72 (39.3%) and 142 (77.6%), 4 (2.2%), 37(20.2%), 60(32.8%), 32 (17.5%), 91 (49.7%) respectively. The distributions of genotypes were all in accordance with the Hardy-Weinberg equilibrium (P > 0.05), with statistical differences and with other ethnic populations (P < 0.05). CONCLUSION: The SNPs of metabolic enzymes can be detected by PCR-CTPP method which is simple, accurate, rapid, economic and with large scale. PCR-CTPP can be used for large scale clinical and epidemiological screening.