2D Ti3C2-MXene Serving as Intermediate Layer between Absorber and Back Contact for Efficient CZTSSe Solar Cells

Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) has been considered as the most promising absorber material for inorganic thin-film solar cells. Among the three main interfaces in CZTSSe-based solar cells, the CZTSSe/Mo back interface plays an essential role in hole extraction as well as device performance. During the selenization process, the reaction between CZTSSe and Mo is one of the main reasons that lead to a large open circuit voltage (VOC) deficit, low short circuit current (Jsc), and fill factor. In this study, 2D Ti3C2-MXene was introduced as an intermediate layer to optimize the interface between the CZTSSe absorber layer and Mo back contact. Benefiting from the 2D Ti3C2-MXene intermediate layer, the reaction between CZTSSe and Mo was effectually suppressed, thus, significantly reducing the thickness of the detrimental Mo(S,Se)2 layer as well as interface recombination at the CZTSSe/Mo back interface. As a result, the power conversion efficiency of the champion device fabricated with the 2D Ti3C2-MXene intermediate layer was improved from 10.89 to 13.14% (active-area efficiency). This study demonstrates the potential use of the 2D Ti3C2-MXene intermediate layer for efficient CZTSSe solar cells and promotes a deeper understanding of the back interface in CZTSSe solar cells.

Suppressing interface recombination in CZTSSe solar cells by simple selenization with synchronous interface gradient doping

The main bottleneck in the development of kesterite Cu₂ZnSn(S,Se)₄ (CZTSSe) solar cells is their very low V_OC due to severe carrier recombination. Specifically, due to the poor defect environment and unfavorable band structure, carrier recombination at the front interface is considered to be one of the most serious issues. Thus, to reduce the interface recombination and V_OC deficit, we propose a convenient and effective strategy for Cd gradient doping near the front interface during selenization. The formed Cd gradient significantly reduced the Cu_Zn defects and related [2Cu_Zn + Sn_Zn] defect clusters near the CZTSSe-CdS heterojunction, thus significantly suppressing the interface recombination near the heterojunction. Benefitting from the formed Cd gradient, a champion device with 12.14% PCE was achieved with the V_OC significantly improved from 432 mV to 486 mV. The proposed element gradient doping strategy can offer a new idea for selenization and element gradient doping in other photoelectric devices.

[Chlamydia psittaci pneumonia complicated with rhabdomyolysis: a case report and literature review]

Objective: To analyze the clinical characteristics and the diagnosis and treatment of Chlamydia psittaci pneumonia complicated with rhabdomyolysis. Methods: We reported a case of Chlamydia psittaci pneumonia complicated with rhabdomyolysis. We did a literature review on the published reports between January 1978 and May 2020 by searching with the key words of "psittacosis" or "Chlamydia psittaci" and "rhabdomyolysis" in the PubMed database (time frame: January 1, 1967 to May 30, 2020). Results: Our patient was a 64-year-old male presenting with high-grade fever, fatigue, myalgia and dyspnea. A computed tomographic scan of the chest revealed bilateral pneumonia, which was further complicated with rhabdomyolysis during disease progression. This prompted the metagenomic next-generation sequencing, revealing the sequences of Chlamydia psittaci in both the bronchoalveolar lavage fluid and blood. Of the 11 cases in the 3 literature reports that we retrieved, 5 had concomitant rhabdomyolysis (two of which did not have complete clinical information), and the other 6 cases had myositis complicated with an elevated level of creatine phosphokinase. This yielded 3 cases with complete clinical information for our analysis. We had further incorporated their information with the single case managed within our study site. Two were males and the other 2 were females. The patients were aged 66, 46, 44 and 64 years, respectively. All cases had fever and 3 had a contact history with live poultry. Two cases had myalgia and progressed rapidly into having respiratory failure, and the other 2 cases did not develop myalgia and improved significantly after a timely treatment. All 4 cases were cured and discharged after treatment with appropriate antibiotics. No adverse outcomes were observed. Conclusions: The prognosis of Chlamydia psittaci pneumonia complicated with rhabdomyolysis was poor in case of a delayed treatment. Early diagnosis would help reduce the mortality.

[Downregulation of large conductance calcium-activated potassium channels in paraventricular nucleus contributes to sympathoexcitation in rats with chronic heart failure]

Objective: To elucidate the association between large conductance calcium-activated potassium channels (BK_Ca) in the paraventricular hypothalamic nucleus (PVN) and sympathetic outflow in rats with chronic heart failure (CHF) . Methods: Male Wistar rats (6-7 weeks old) were randomized to sham operated group and CHF group (coronary artery ligation) . Two weeks after operation, BK_Ca inhibitor Iberiotoxin (IBTX) was infused into PVN by osmotic minipumps, rats were divided into following groups: sham+aCSF, CHF+aCSF, sham+low dose IBTX (0.125 nmol/nl) , CHF+low dose IBTX, sham+moderate dose IBTX (1.25 nmol/nl) , CHF+moderate dose IBTX, sham+ high dose IBTX (12.5 nmol/nl) , and CHF+high dose IBTX (n=6 each) . Additional rats were grouped as follows: sham+vehicle, sham+KCNMB4 knockdown (by rAAV2-KCNMB4 shRNA virus injection in PVN) , CHF+vehicle, CHF+ KCNMB4 knockdown group (n=6 each) . The cardiac function was determined by echocardiography, left ventricular hemodynamics were measured invasively, renal sympathetic nerve activity (RSNA) was recorded at 6 weeks after coronary artery ligation or sham operation. The contents of norepinephrine (NE) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in plasma were determined by enzyme-linked immunosorbent assay. The protein and mRNA expression of KCNMB4 in PVN were measured by immunofluorescence staining, Western blot, and real-time PCR, mRNA expression of BK_Ca in PVN was detected by real-time PCR. Results: Compared with the sham operation group, the cardiac function of the heart failure group was significantly reduced (P<0.05) , and the plasma NE and the serum NT-proBNP were significantly elevated (P<0.05) . The protein and mRNA expression of KCNMB4 in PVN were obviously down-regulated in CHF rats (P<0.05) . After perfusion of IBTX or KCNMB4 knockdown by microinjection of rAAV2-KCNMB4 shRNA virus,right ventricular weight/body weight and lung weight/body weight ratio as well as left ventricular end-diastolic diameter were increased and left ventricular ejection fraction was decreased (all P<0.05) , the sympathetic driving indexes was increased in sham rats, changes of these parameters further aggravated in CHF rats (P<0.05) . KCNMB4 knockdown further downregulated protein expression in PVN of CHF rats. Conclusion: Downregulation and blunted function of BK_Ca in PVN may contribute to sympathoexcitation and deterioration of cardiac function in rats with chronic heart failure.

[Role and mechanism of hydrogen sulfide in cigarette smoke induced chronic obstructive pulmonary disease related pulmonary vascular remodeling in rats]

Objective: To investigate the role and mechanism of hydrogen sulfide (H2S) in rats with chronic obstructive pulmonary disease (COPD) related pulmonary vascular remodeling. Methods: Twenty four healthy male Sprague-Dawley rats were randomly divided into 4 groups: control group, cigarette smoke (CS) group, CS+ Sodium hydrosulfide (NaHS) group and CS+ DL-propargylglycine (PPG) group. Rats in control group were fed normally and breathed clear air, and for the rest groups, passive cigarette smoke inhalation method were adopted to establish COPD model. After 8 weeks, the rats in corresponding groups were treated by NaHS or PPG. After 16 weeks, the markers of pulmonary vascular remodeling in all groups were measured. Proliferation marker proliferative cell nuclear antigen (PCNA) and oxidative stress marker 3-neurotrophin (3-NT) in all groups were measured by immunohistochemistry (IHC). Results: Compared with control group, the airway resistance was increased (0.859±0.283 vs 0.578±0.088, P<0.05) and the pathological scores was much higher in CS group, which suggested that the COPD model was successful. The degree of small resistance pulmonary artery medial wall thickness and full vascular muscularization of CS group were much higher (0.54±0.20 vs 0.37±0.12, 0.39±0.08; 0.61±0.16 vs 0.20±0.12, 0.34±0.13, all P<0.01)than control group and CS+ NaHS group, there was no significant difference between CS+ PPG group and CS group. In accordance with the results of morphometric analysis, the proliferation marker PCNA was more in CS group when compared with control group and CS+ NaHS group (0.27±0.08 vs 0.12±0.06, 0.14±0.06, both P<0.05), there was no significant difference between CS+ PPG group and CS group. Furthermore, the IHC also showed that 3-NT significantly increased in CS group compared with control group and CS+ NaHS group (0.26±0.08 vs 0.18±0.04, 0.19±0.06, both P<0.01), there was no significant difference between CS+ PPG group and CS group as well. In addition, the small resistance pulmonary artery medial wall thickness had strong correlation with the expression level of oxidative stress marker 3-NT (r=0.906, P<0.001). Conclusion: H2S significantly attenuates cigarette smoke induced COPD related pulmonary vascular remodeling, which could be related to its ability to decrease oxidative stress.

Primary malignant fibrous histiocytoma of the thyroid

AIMS AND METHODS

To study the clinical features, diagnosis, and treatment of primary malignant fibrous histiocytoma of the thyroid (MFH-T). Treatment and outcome were analyzed retrospectively in a consecutive series of 12 patients with primary MFH-T treated at the Cancer Hospital of the Chinese Academy of Medical Sciences from 1987 to 2007.

RESULTS

All 12 patients underwent surgery; surgery alone was used in four patients. Five patients were given post-operative radiotherapy, and one patient was given pre-operative radiotherapy. Two patients were given post-operative chemotherapy. Five patients had locoregional recurrence, and five had distant metastases in follow-up. Median survival was 9 months. One patient is alive, and has no evidence of disease. Six patients died six months after treatment, and the other four patients died in 10, 14, 18, and 24 months after treatment, respectively. Nine patients died of the disease, and one patient died of cerebral hemorrhage after treatment.

CONCLUSION

Primary MFH-T is very rare and has a poor prognosis. Although surgical resection of MFH-T is the treatment of choice in MFH-T, the results are unsatisfactory.

The role of adrenomedullin and its receptor system in cardiovascular calcification of rat induced by Vitamin D(3) plus nicotine

Adrenomedullin (ADM) is a potent vasodilatory peptide which regulates blood pressure, cell growth and bone formation. Our work was aimed to explore the production of ADM, changes and pathophysiological significance of ADM mRNA and ADM receptor components--calcitonin receptor like receptor (CRLR) and receptor activity modifying proteins (RAMPs) mRNA in calcified myocardium and aorta of rats induced by Vitamin D3 plus nicotine. Contents of ADM in plasma, myocardium and aorta were measured by radioimmunoassay (RIA). The amount of ADM, CRLR and RAMPs mRNA was determined by semi-quantitative RT-PCR. The calcium content and alkaline phosphatase activity in myocardium and aorta of rats were measured. The results showed that the contents of calcium in calcified myocardium and aorta were increased by 3.5- and 6-fold (all P < 0.01), respectively, and alkaline phosphatases activity in calcified myocardium and aorta were increased by 66.5 and 82.7% (all P < 0.01 ), respectively, compared with control. Contents of ADM in plasma, myocardium and aorta were increased by 58% (P < 0.01), 14.3% (P < 0.01) and 27.8% P < 0.05). Furthermore, it was found that the amount of ADM, CRLR and RAMP2 mRNA in calcified myocardium was elevated by 90.6, 157.5 and 119.6% (all P < 0.01), RAMP3 mRNA was decreased by 14.1% (P < 0.01), respectively, compared with control. The amount of ADM, CRLR, RAMP2 and RAMP3 mRNA in calcified aorta was elevated by 37.7% (P < 0.01), 41.4% (P < 0.01), 60.1% (P < 0.05) and 13% P < 0.01), respectively, compared with control. The elevated level of CRLR and RAMP2 mRNA were in positive correlation with that of ADM mRNA (r = 0.992 and 0.882, respectively, P < 0.01) in calcified myocardium. The elevated level of CRLR and RAMP3 mRNA were also in positive correlation with that of ADM mRNA (r = 0.727, P < 0.05 and 0.816, P < 0.01, respectively) in calcified aorta. These results demonstrated that calcified myocardium and aorta generated an increased amount of ADM, up-regulated gene expressions of ADM, CRLR and RAMP2 mRNA. While the alteration of RAMP3 mRNA in calcified myocardium and aorta was different. These suggested that ADM and its receptor system might involve in the regulation of calcification in heart and aorta.

Desensitization of adrenomedullin and calcitonin gene-related peptide receptors in vascular smooth muscle cells--effects of receptor activity-modifying protein

Recent researches suggest that adrenomedullin (ADM) and calcitonin gene-related peptide (CGRP) bind to the same calcitonin receptor-like receptors (CRLR), with receptor specificity being determined by a receptor activity-modifying protein (RAMP). Our objective was to explore the significance of CRLR/RAMP hypothesis in cardiovascular tissues through experiments on the phenomenon of desensitization of both ADM and CGRP receptors using cultured rat aortic vascular smooth muscle cells (VSMCs). VSMCs were incubated for 20 min either in serum-free medium (SFM) alone or in the SFM containing vasoactive agonist [10(-8) mol/L ADM, CGRP and proadrenomedullin (PAMP)]. Cells were washed twice and incubated for another 20 min in SFM containing a repetitive agonist ADM or CGRP and 0.5 mmol/L isobutyryl methylxant (an inhibitor of phosphodiesterase). VSMCs were harvested and assayed for cAMP. Exposure of VSMCs to ADM, CGRP, or PAMP alone increased intracellular cAMP generation by 191% (P < 0.01), 385% (P < 0.01) and 67% (P < 0.05), respectively, compared with SFM group. Pre-treatment of VSMCs to ADM or CGRP decreased cAMP generation in response to subsequent stimulation with CGRP by 44% (P < 0.05) and 48% (P < 0.01), respectively. Pre-treatment of VSMCs with 100 nmol/L H-89, a protein kinase A (PKA) inhibitor, abolished the desensitization of CGRP-acting receptor, implying that this desensitization was mediated through PKA. In contrast, there was no attenuation in cAMP response to stimulation with ADM by pre-exposure to ADM or CGRP. Identical results were seen with or without PKA inhibition by H-89. Pre-exposure of VSMCs to PAMP resulted in no change in cAMP generation in response to subsequent stimulation with ADM or CGRP. These results indicate that ADM receptors do not desensitize in VSMCs in contrast to CGRP-receptors, which are desensitized by pre-exposure to ADM or CGRP. These data also suggest that the desensitization phenomenon of ADM is different from that of CGRP.

[Ameliorative effects of adrenomedullin on rat cardiac sarcoplasmic reticulum injured by isoproterenol]

Five indices were used to assess the degree of the ameliorative effects of adrenomedullin (Adm) in isoproterenol (ISO) induced injury of cardiac sarcoplasmic reticulum (SR) of rats: +/- LV dp/dtmax, SR Ca2+ uptake, Ca2+ release (in nmol/mg SR protein) and Ca(2+)-ATPase activity. Adm (5 x 10(-5) mol/L) was perfused into rat heart before cardiac function +/- LV dp/dtmax was determined. Cardiac SR was purified and SR Ca2+ uptake, Ca2+ release, Ca(2+)-ATPase activity, and 3H-ryanodine maximal binding (Bmax) were measured. After perfusion of Adm (5 x 10(-5) mol/L), the +LV dp/dtmax and -LV dp/dtmax in ISO injured heart were increased by 16.9% (2,135 +/- 281 vs 1980 +/- 302, P < 0.05) and 29.2% (1375 +/- 267 vs 1064 +/- 355, P < 0.05), respectively. Cardiac SR Ca2+ uptake and Ca2+ release were increased by 23.0% (15.0 +/- 1.4 vs 12.2 +/- 1.2, P < 0.01) and 43.5% (6.6 +/- 1.0 vs 4.6 +/- 0.6, P < 0.01), respectively. Ca(2+)-ATPase activity and 3H-ryanodine binding were increased by 23.0% (P < 0.01) and 42.2% (P < 0.05), respectively. It seems that Adm exerted a protective effect on cardiac function in injured rat heart by enhancing SR Ca2+ uptake and release, suggesting that Adm may play a therapeutic role in myocardial injury.

[Experimental study on xiaoliu pingyi mixture with medicated serum in inducing apoptosis of human hepatocellular carcinoma cell line H-7402]

OBJECTIVE

To observe the efficacy of Xiaoliu Pingyi Mixture (XLPY) in inducing the apoptosis of human hepatocellular carcinoma (HCC) cell line H-7402.

METHODS

Using serum pharmacologic method, the morphological change of apoptotic cells was observed at different time points by co-culturing with different concentrations of medicated serum containing XLPY with light and fluorescent microscopy, flow cytometry, and immunohistochemical staining methods. Blank serum was taken as control.

RESULTS

The different concentration of medicated serum containing XLPY could significantly inhibit the growth of H-7402 cell line in vitro. After treated with medicated serum of XLPY, the cellular morphologic changes were typical apoptosis under light and fluorescent microscopy, the sub-G1 peaks were observed by flow cytometric assays. The apoptosis rate revealed a medicated serum concentration and time dependent manner. The control group 5%, 10% medicated serum induced apoptotic rate were 0.49%, 5.58% and 8.46% by 24 h; while by 48 h, it was 0.83%, 11.58% and 14.25% respectively. bcl-2 gene examination showed that the bcl-2 gene expression was inhibited.

CONCLUSION

XLPY could induce apoptosis in carcinoma cells, and play the clinical role of anti-tumor and anti-metastasis.

[The biochemical properties of L-arginine/nitric oxide pathway in rat brain mitochondria]

Biochemical property of L-arginine (L-Arg)/nitric oxide synthase (NOS)/nitric oxide (NO) system was observed in rat brain mitochondria. The results showed that there existed L-Arg transporters of high-affinity, low-transport and saturability in mitochondria membrane of normal rat brain. The maximum transport velocity (V(max)) and Michaelis constant (Km) were 5.87+/ -0.46 nmol/mg pro x min(-1) and 7.8+/- 0.56 micromol/L respectively. In normal condition, endothelium-type NOS was expressed in the mitochondria of rat brain, with its V(max) and Km being 2.7+/-0.3 nmol/mg pro x min(- 1) and 20.85+/-3.27 micromol/L, respectively. NO production was increased in a time-dependent manner and reached a maximum value at 60 min. These results suggest that the L-Arg transporters in MT membrane of normal rat brain were similar with Y(+) type amino acid transporters in cellullar membrane. Furthermore the NOS of mitochondria belongs to eNOS, whereas the L-Arg/NOS/NO system may be a source of NO.

[Clinical observation of the effect of blood gas with two different methods of sputum suction]

The authors observed the preventive effect of the oxygen supplied double channel sucker on low blood oxygen. Thirty patients with channel sputum sucker under the mechanical respiratory support were taken as the contrast group, in comparison with the experimental group A and B respectively. Patients (n = 30) with one channel sputum sucking for 15 sec. were designated as experimental group A, while the other patients (n = 30) with the oxygen supplied double channel sucking for 15 sec were the group B, Blood gas analysis was done in every patient of each group. Significant difference of PO2 was found between group A and the contrast group (P < 0.01). No significant difference was found between group B and the contrast group (P > 0.05). It shows that oxygen supplied double channel sucker has preventive effect on low blood oxygen, and is suitable for sputum sucking in severe patients.