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Deciphering the Roles of MA-Based Volatile Additives for α-FAPbI 3 to Enable Efficient Inverted Perovskite Solar Cells. J Am Chem Soc 2023; 145:5920-5929. [PMID: 36877962 DOI: 10.1021/jacs.2c13566] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Functional additives that can interact with the perovskite precursors to form the intermediate phase have been proven essential in obtaining uniform and stable α-FAPbI3 films. Among them, Cl-based volatile additives are the most prevalent in the literature. However, their exact role is still unclear, especially in inverted perovskite solar cells (PSCs). In this work, we have systematically studied the functions of Cl-based volatile additives and MA-based additives in formamidinium lead iodide (FAPbI3)-based inverted PSCs. Using in situ photoluminescence, we provide clear evidence to unravel the different roles of volatile additives (NH4Cl, FACl, and MACl) and MA-based additives (MACl, MABr, and MAI) in the nucleation, crystallization, and phase transition of FAPbI3. Three different kinds of crystallization routes are proposed based on the above additives. The non-MA volatile additives (NH4Cl and FACl) were found to promote crystallization and lower the phase-transition temperatures. The MA-based additives could quickly induce MA-rich nuclei to form pure α-phase FAPbI3 and dramatically reduce phase-transition temperatures. Furthermore, volatile MACl provides a unique effect on promoting the growth of secondary crystallization during annealing. The optimized solar cells with MACl can achieve an efficiency of 23.1%, which is the highest in inverted FAPbI3-based PSCs.
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Pathogenesis, Experimental Models and Contemporary Pharmacotherapy of Irritable Bowel Syndrome: Story About the Brain-Gut Axis. Curr Neuropharmacol 2017; 14:842-856. [PMID: 27009115 PMCID: PMC5333584 DOI: 10.2174/1570159x14666160324144154] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 02/07/2016] [Accepted: 03/22/2016] [Indexed: 11/22/2022] Open
Abstract
Background Although the precise pathophysiology of irritable bowel syndrome (IBS) remains unknown, it is generally considered to be a disorder of the brain-gut axis, representing the disruption of communication between the brain and the digestive system. The present review describes advances in understanding the pathophysiology and experimental approaches in studying IBS, as well as providing an update of the therapies targeting brain-gut axis in the treatment of the disease. Methods Causal factors of IBS are reviewed. Following this, the preclinical experimental models of IBS will be introduced. Besides, both current and future therapeutic approaches of IBS will be discussed. Results When signal of the brain-gut axis becomes misinterpreted, it may lead to dysregulation of both central and enteric nervous systems, altered intestinal motility, increased visceral sensitivity and consequently contributing to the development of IBS. Interference of the brain-gut axis can be modulated by various psychological and environmental factors. Although there is no existing animal experiment that can represent this complex multifactorial disease, these in vivo models are clinically relevant readouts of gastrointestinal functions being essential to the identification of effective treatments of IBS symptoms as well as their molecular targets. Understanding the brain-gut axis is essential in developing the effective therapy for IBS. Therapies include improvement of GI motor functions, relief of visceral hypersensitivity and pain, attenuation of autonomic dysfunctions and suppression of mucosal immune activation. Conclusion Target-oriented therapies that provide symptomatic, psychological and physiological benefits could surely help to improve the quality of life of IBS patients.
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Increased basal insulin secretion in Pdzd2-deficient mice. Mol Cell Endocrinol 2010; 315:263-70. [PMID: 19932150 DOI: 10.1016/j.mce.2009.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 11/12/2009] [Accepted: 11/12/2009] [Indexed: 10/20/2022]
Abstract
Expression of the multi-PDZ protein Pdzd2 (PDZ domain-containing protein 2) is enriched in pancreatic islet beta cells, but not in exocrine or alpha cells, suggesting a role for Pdzd2 in the regulation of pancreatic beta-cell function. To explore the in vivo function of Pdzd2, Pdzd2-deficient mice were generated. Homozygous Pdzd2 mutant mice were viable and their gross morphology appeared normal. Interestingly, Pdzd2-deficient mice showed enhanced glucose tolerance in intraperitoneal glucose tolerance tests and their plasma insulin levels indicated increased basal insulin secretion after fasting. Moreover, insulin release from mutant pancreatic islets was found to be twofold higher than from normal islets. To verify the functional defect in vitro, Pdzd2 was depleted in INS-1E cells using two siRNA duplexes. Pdzd2-depleted INS-1E cells also displayed increased insulin secretion at low concentrations of glucose. Our results provide the first evidence that Pdzd2 is required for normal regulation of basal insulin secretion.
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mab-7 encodes a novel transmembrane protein that orchestrates sensory ray morphogenesis in C. elegans. Dev Biol 2007; 312:353-66. [PMID: 17959165 DOI: 10.1016/j.ydbio.2007.09.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2007] [Revised: 09/08/2007] [Accepted: 09/18/2007] [Indexed: 10/22/2022]
Abstract
The tapered sensory rays of the male Caenorhabditis elegans are important for successful male/hermaphrodite copulation. A group of ram (ray morphology abnormal) genes encoding modifying enzymes and transmembrane protein have been reported as key regulators controlling ray morphogenesis. Here we report the characterization of another component essential for this morphogenetic process encoded by mab-7. This gene is active in the hypodermis, structural cells, the body seam and several head neurons. It encodes a novel protein with a hydrophobic region at the N-terminus, an EGF-like motif, an ShKT motif and a long C-terminal tail. All these domains are shown to be critical to MAB-7 activity except the EGF-like domain, which appears to be regulatory and dispensable. MAB-7 is shown to be a type II membrane protein, tethered on the cell surface by the N-terminal transmembrane domain with the remainder of the protein exposed to the extracellular matrix. Since ectopic mab-7 expression in any ray cell or even in touch neurons of non-ray lineage can rescue the mutant phenotype, mab-7 is probably acting non-autonomously. It may facilitate intercellular communication among ray cells to augment normal ray morphogenesis.
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An audit on hysterectomy for benign diseases in public hospitals in Hong Kong. Hong Kong Med J 2007; 13:187-93. [PMID: 17548906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
OBJECTIVE To assess the standard of hysterectomy in public hospitals in Hong Kong, so as to improve the quality of patient care and outcome. DESIGN Clinical audit. SETTING Twelve Hong Kong Hospital Authority public hospitals. PATIENTS All patients undergoing hysterectomy for benign gynaecological conditions during the period from 1 July 2002 to 31 December 2002 inclusive. RESULTS A total of 1330 patients were included for analysis: 934 (70.2%) having abdominal hysterectomies, 184 (13.8%) having laparoscopic hysterectomies, and 212 (15.9%) undergoing vaginal hysterectomies. Uterine fibroids constituted the commonest indication for abdominal (73.7%) and laparoscopic (61.4%) hysterectomies, while genital prolapse was the most common indication (96.2%) for vaginal hysterectomy. The majority of patients undergoing laparoscopic and vaginal hysterectomy (86.3% and 84.8% respectively) were given prophylactic antibiotics, in contrast to only 45.8% of those undergoing abdominal hysterectomy. In all, 85.8% of the abdominal and vaginal hysterectomies performed by trainees were supervised, while for trainees performing laparoscopic hysterectomy, all had specialists as their first assistant. The overall incidence of complications for vaginal hysterectomy was lower than that for both abdominal hysterectomy (P<0.001) and laparoscopic hysterectomy (P<0.05). Infectious morbidity was significantly higher in patients undergoing abdominal hysterectomy without prophylactic antibiotics. CONCLUSION The overall incidence of complications was lower for vaginal hysterectomies, as compared to both abdominal and laparoscopic hysterectomies, whereas the risk of urinary tract injury was significantly higher for laparoscopic hysterectomy. According to our audit, the level of supervision for the trainees was high. However, routine antibiotic prophylaxis should be more consistently used in the territory.
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Loss of serotonin 5-HT2A receptors in the postmortem temporal cortex correlates with rate of cognitive decline in Alzheimer's disease. Psychopharmacology (Berl) 2005; 179:673-7. [PMID: 15551121 DOI: 10.1007/s00213-004-2077-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2004] [Accepted: 10/06/2004] [Indexed: 10/26/2022]
Abstract
RATIONALE Previous studies have demonstrated reductions of serotonin 5-HT 2A receptors in the neocortex of Alzheimer's disease (AD) patients. However, it is unclear whether such losses play a role in the cognitive decline of AD. OBJECTIVES To correlate neocortical 5-HT 2A receptor alterations with cognitive decline in AD. METHODS Postmortem frontal and temporal cortical 5-HT 2A receptors were measured by [3H]ketanserin binding in aged controls as well as in a cohort of AD patients who had been longitudinally assessed for cognitive decline and behavioral symptoms. RESULTS 5-HT 2A receptor densities in both regions were reduced in severely demented AD patients compared to age-matched controls. In the temporal cortex, this reduction also correlated with the rate of decline of Mini-Mental State Examination (MMSE) scores. The association between 5-HT 2A receptor loss and cognitive decline was independent of the effects of choline acetyltransferase (ChAT) activity and presence of behavioral symptoms. CONCLUSIONS Our data suggest that loss of neocortical 5-HT 2A receptors may predict for faster cognitive decline in AD, and point to serotomimetics as potentially useful adjuvants to cholinergic replacement therapies.
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[3H]GR113808 binding to serotonin 5-HT(4) receptors in the postmortem neocortex of Alzheimer disease: a clinicopathological study. J Neural Transm (Vienna) 2003; 110:779-88. [PMID: 12811638 DOI: 10.1007/s00702-003-0825-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Abnormalities in neural transmission of serotonin (5-HT) may play a role in both cognitive and neuropsychiatric features of Alzheimer disease (AD). We measured 5-HT(4) receptors in the postmortem frontal and temporal cortex of 34 AD subjects and 15 controls by radioligand binding with [3H]GR113808. Receptor binding data was then correlated with prospectively assessed cognitive (Mini-Mental State Examination, MMSE) and behavioral (Present Behavioural Examination, PBE) data. [3H]GR113808 binding affinity (K(D)) and density (B(max)) in AD were unchanged compared to controls in both cortical regions, and did not correlate with MMSE or PBE data. The binding parameters were also not related to disease duration, senile plaque and neurofibrillary tangle counts, and neuroleptic medication. We conclude that unlike other 5-HT receptors, 5-HT(4) receptor binding affinity and density do not seem to be affected in the frontal and temporal cortex in AD and may not have a direct role in the clinical features of the disease.
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Lamivudine treatment for fulminant hepatic failure due to acute exacerbation of chronic hepatitis B infection. Aliment Pharmacol Ther 2001; 15:1737-44. [PMID: 11683687 DOI: 10.1046/j.1365-2036.2001.01107.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Exacerbation of chronic hepatitis B infection can lead to fulminant hepatic failure with a mortality of up to 90%. AIM To evaluate the efficacy of lamivudine in the treatment of this subgroup of patients. METHODS Twenty-four patients with exacerbation of chronic hepatitis B infection and fulminant hepatic failure were treated with lamivudine, 100 mg daily. Hepatitis A, C, D and human immunodeficiency virus co-infections and hepatocellular carcinoma were excluded. RESULTS The median age was 53 years (range, 24-77 years) with a male predominance of 20:4. Seventeen patients were hepatitis B e antigen positive. Mean hepatitis B virus DNA was 2079 Meq/mL. Eight patients (33%) survived (group A). Thirteen patients died and three patients received liver transplantation (67%) (group B). Baseline laboratory results were comparable between the two groups, including serum albumin, bilirubin, alanine aminotransferase, prothrombin time and creatinine. Group B patients had significantly more comorbid illnesses at baseline and more complications, including sepsis and renal failure, compared with group A patients. Six out of eight survivors (75%) had full hepatitis B e antigen seroconversion, but this was not sustained in four patients. CONCLUSIONS Lamivudine may be useful in treating patients with fulminant hepatic failure due to exacerbation of chronic hepatitis B. Hepatitis B e antigen seroconversion was less durable in this subgroup of patients and long-term therapy may be required.
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Abstract
Lactose, the major carbohydrate of human milk, is synthesized in the Golgi from glucose and UDP-galactose. The lactating mammary gland is unique in its requirement for the transport of glucose into Golgi. Glucose transporter-1 (GLUT1) is the only isoform of the glucose transporter family expressed in mammary gland. In most cells, GLUT1 is localized to the plasma membrane and is responsible for basal glucose uptake; in no other cell type is GLUT1 a Golgi resident. To test the hypothesis that GLUT1 is targeted to Golgi during lactation, the amount and subcellular distribution of GLUT1 were examined in mouse mammary gland at different developmental stages. Methods including immunohistochemistry, immunofluorescence, subcellular fractionation, density gradient centrifugation, and Western blotting yielded consistent results. In virgins, GLUT1 expression was limited to plasma membrane of epithelial cells. In late pregnant mice, GLUT1 expression was increased with targeting primarily to basolateral plasma membrane but also with some intracellular signal. During lactation, GLUT expression was further increased, and targeting to Golgi, demonstrated by colocalization with the 110-kD coatomer-associated protein beta-COP, predominated. Removal of pups 18 d after delivery resulted in retargeting of GLUT1 from Golgi to plasma membrane and a decline in total cellular GLUT1 within 3 h. In mice undergoing natural weaning, GLUT1 expression declined. Changes in the amount and targeting of GLUT1 during mammary gland development are consistent with a key role for GLUT1 in supplying substrate for lactose synthesis and milk production.
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Abstract
BACKGROUND Hepatitis B (HBV)-infected patients have a higher morbidity and mortality when super-infected by hepatitis A (HAV). AIM To evaluate the immunogenicity and safety of a commercial inactivated HAV vaccine in Chinese patients with chronic HBV infection. METHODS Sixty-five HBV-infected patients (30 carriers, 22 chronic hepatitis, 13 cirrhosis), who were seronegative for HAV, received a dose of 1440 ELISA units of HAV vaccine at weeks 0 and 24. Twenty-eight healthy individuals aged 18-57 years, who were seronegative for both HBV and HAV infection, also received the same vaccination regimen. Seroconversion was defined as an anti-HAV titre >/= 33 mIU/mL. RESULTS The seroconversion rates for the HBV-infected patients at weeks 2, 4 and 24 were 72, 91 and 80%, respectively. The corresponding geometric mean titres (GMTs) were 103, 311 and 123 mIU/mL. In the healthy control group the seroconversion rates were 86, 93 and 89% at weeks 2, 4 and 24. The corresponding GMTs were 112, 158 and 250 mIU/mL. There was no difference in the seroconversion rates between the two groups, but healthy controls had a significantly higher GMT at week 24 (P=0.04). Side-effects were more common in HBV patients. CONCLUSION The HAV vaccine is equally efficacious in patients with chronic HBV infection.
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Abstract
BACKGROUND Gene deletion, point mutations, and abnormalities in expression of the tumor suppressor gene p53 in hepatocellular carcinoma have been reported to occur with varying frequency in different geographic regions. METHODS To assess the expression and point mutation of the p53 gene, 31 patients with hepatocellular carcinomas were examined using Northern blotting, immunohistochemical methods, and DNA sequencing. All patients were Chinese, and 90.3% were positive for hepatitis B surface antigen (HBsAg). RESULTS p53 transcript or protein was found in 14 (48.4%) of the 31 patients. Detectable p53 mRNA transcripts were found in 10 patients, and p53 protein was detected in 8 patients. In most cases of patients who had detectable p53 mRNA transcripts, the transcripts in the tumors were exhibited at a higher level than they were in the corresponding nontumorous livers. No p53 protein was detected in the nontumorous livers in all 31 patients. Six (23.1%) of the 26 tumors sequenced showed point mutation scattered in exons 5-9. Of these, only two were at codon-249, and the nature of these two mutations was G-to-T transversions. All but one of the six patients with point mutations had overexpression of the gene. CONCLUSIONS Our results show that scattered point mutations are not uncommon in hepatocellular carcinomas in patients from Hong Kong. The distribution pattern of the mutations seems to have no particular correlation with HBsAg status despite a high prevalence rate of HBsAg positivity in our patients. Consistent with a low aflatoxin exposure, aflatoxin-related specific mutation at codon-249 is much less related to the pathogenesis of hepatocellular carcinoma in Hong Kong Chinese people than in other regions with a high-aflatoxin exposure.
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Abstract
BACKGROUND Gene deletion, point mutations, and abnormalities in expression of the tumor suppressor gene p53 in hepatocellular carcinoma have been reported to occur with varying frequency in different geographic regions. METHODS To assess the expression and point mutation of the p53 gene, 31 patients with hepatocellular carcinomas were examined using Northern blotting, immunohistochemical methods, and DNA sequencing. All patients were Chinese, and 90.3% were positive for hepatitis B surface antigen (HBsAg). RESULTS p53 transcript or protein was found in 14 (48.4%) of the 31 patients. Detectable p53 mRNA transcripts were found in 10 patients, and p53 protein was detected in 8 patients. In most cases of patients who had detectable p53 mRNA transcripts, the transcripts in the tumors were exhibited at a higher level than they were in the corresponding nontumorous livers. No p53 protein was detected in the nontumorous livers in all 31 patients. Six (23.1%) of the 26 tumors sequenced showed point mutation scattered in exons 5-9. Of these, only two were at codon-249, and the nature of these two mutations was G-to-T transversions. All but one of the six patients with point mutations had overexpression of the gene. CONCLUSIONS Our results show that scattered point mutations are not uncommon in hepatocellular carcinomas in patients from Hong Kong. The distribution pattern of the mutations seems to have no particular correlation with HBsAg status despite a high prevalence rate of HBsAg positivity in our patients. Consistent with a low aflatoxin exposure, aflatoxin-related specific mutation at codon-249 is much less related to the pathogenesis of hepatocellular carcinoma in Hong Kong Chinese people than in other regions with a high-aflatoxin exposure.
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p53 gene mutation spectrum in hepatocellular carcinomas in Hong Kong Chinese. Oncogene 1994; 9:985-90. [PMID: 8108145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To examine the significance of mutation of the p53 tumour suppressor gene in the development of human hepatocellular carcinoma in a high-prevalence area for hepatitis B viral infection but a low-exposure area for aflatoxin B1, the spectrum of p53 gene mutations was examined in 21 tumour samples from Hong Kong Chinese patients, all of whom were HBsAg positive. DNA sequencing covering exons 5 to 9 of the p53 gene and Hae III restriction enzyme digestion for preliminary assessment of mutation at codon 249 were performed. Immunohistochemical staining with anti-p53 monoclonal antibodies was done on both tumour and nontumour liver tissues. Six tumours (28.6%) showed a p53 mutation and all were point mutations. Of the six point mutations, two (9.5%) were at codon 249 and both were G to T transversions (AGG-->ATG and AGG-->AGT transversions). The remaining point mutations were transversions scattered at codon 172 (exon 5), 214 (exon 6), 273 (exon 8) and 330 (exon 9). Mutated p53 protein was detected in five of these six cases with demonstrable point mutations by DNA sequencing, in contrast to none detected in all of the 15 cases without demonstrable point mutations. The presence of p53 mutations, including those at codon 249, did not show a significant association with tumour size, sex, age, tumour invasiveness in terms of liver invasion, microsatellites and venous permeation, cirrhosis and encapsulation, but tumours with low cellular differentiation tended to have a higher incidence (71%) of point mutations than those with high cellular differentiation (8%). In conclusion, both the overall p53 mutation rate and that a codon 249 in HCC in Hong Kong Chinese are lower than those reported in tumours from China and sub-Saharan Africa. The low mutation rate at codon 249 is compatible with a low aflatoxin exposure. A special type of p53 mutation has not been found to be associated with hepatitis B viral infection. Mutations of p53 gene tends to occur in tumours with low cellular differentiation, suggesting a late occurrence in the event of tumour progression.
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