Thermodynamic origin of instability in hybrid halide perovskites

Degradation of hybrid halide perovskites under the influence of environmental factors impairs future prospects of using these materials as absorbers in solar cells. First principle calculations can be used as a guideline in search of new materials, provided we can rely on their predictive capabilities. We show that the instability of perovskites can be captured using ab initio total energy calculations for reactants and products augmented with additional thermodynamic data to account for finite temperature effects. Calculations suggest that the instability of CH₃NH₃PbI₃ in moist environment is linked to the aqueous solubility of the CH₃NH₃I salt, thus making other perovskite materials with soluble decomposition products prone to degradation. Properties of NH₃OHPbI₃, NH₃NH₂PbI₃, PH₄PbI₃, SbH₄PbI₃, CsPbBr₃, and a new hypothetical SF₃PbI₃ perovskite are studied in the search for alternative solar cell absorber materials with enhanced chemical stability.

[Effect of standardized treatment on reactivity of toe microcirculation in patients with type 2 diabetes mellitus]

OBJECTIVE

To evaluate the effect of standardized treatment on reactivity of the lower limb terminal microcirculation in patients with type 2 diabetes mellitus (T2DM) by high frequency ultrasound combined with warm bath.

METHODS

A total of 66 patients with T2DM were collected from June 2014 to May 2015 in the Second Affiliated Hospital of Wenzhou Medical University.According to the vascular complications , the patients were divided into group A without complications (36 cases)and group B with complications (30 cases). Hemodynamic parameters such as peak systolic velocity(PSV), end-diastolic velocity(EDV) and resistance index(RI) of the right plantar digital artery on fibular side of the 1st toe were acquired through Doppler in all subjects.Then the above operation were performed repetitively on all subjects after the right foot was immersed in 40 ℃ warm water for 5 minutes.The change rates of PSV, EDV and RI were calculated after warm bath.All subjects were examined again after three months treatment .The growth rates of the change rate of PSV, EDV and RI were calculated after treatment.All parameters were analyzed.

RESULTS

The change rates of the parameters in group B before and after treatment were lower than those of group A, before treatment (0.108±0.077 vs 0.184±0.091, P=0.037, 0.184±0.101 vs 0.380±0.167, P=0.002, 0.007±0.004 vs 0.015±0.008, P=0.028 7), after treatment (0.155±0.111 vs 0.421±0.138, 0.287±0.108 vs 0.794±0.286, 0.012±0.008 vs 0.039±0.014, P=0.000); the post treatment growth rates of the change rates of the parameters in group B were all less than those of group A (0.414±0.303 vs 2.192±2.673, P=0.048, 0.660±0.406 vs 1.422±1.075, P=0.042, 0.633±0.830 vs 2.191±2.269, P=0.048). The change rates of the parameters in two groups after treatment were higher than those before treatment (all P<0.05).

CONCLUSION

Warm bath test can be used to detect change degree of hemodynamic parameters in patients with T2DM so as to evaluate reactivity of blood microcirculation, which has a certain clinical application value in treatment.

Local proliferation initiates macrophage accumulation in adipose tissue during obesity

Obesity-associated chronic inflammation is characterized by an accumulation of adipose tissue macrophages (ATMs). It is generally believed that those macrophages are derived from peripheral blood monocytes. However, recent studies suggest that local proliferation of macrophages is responsible for ATM accumulation. In the present study, we revealed that both migration and proliferation contribute to ATM accumulation during obesity development. We show that there is a significant increase in ATMs at the early stage of obesity, which is largely due to an enhanced in situ macrophage proliferation. This result was obtained by employing fat-shielded irradiation and bone marrow reconstitution. Additionally, the production of CCL2, a pivotal chemoattractant of monocytes, was not found to be increased at this stage, corroborating with a critical role of proliferation. Nonetheless, as obesity proceeds, the role of monocyte migration into adipose tissue becomes more significant and those new immigrants further proliferate locally. These proliferating ATMs mainly reside in crown-like structures formed by macrophages surrounding dead adipocytes. We further showed that IL-4/STAT6 is a driving force for ATM proliferation. Therefore, we demonstrated that local proliferation of resident macrophages contributes to ATM accumulation during obesity development and has a key role in obesity-associated inflammation.

Relationship between HLA-DP gene polymorphisms and the risk of hepatocellular carcinoma: a meta-analysis

The association between the HLA-DP single nucleotide polymorphisms (SNPs) rs3077 and rs9277535 and hepatocellular carcinoma (HCC) has been reported, but results have been inconclusive and controversial. Therefore, to investigate the relationship between these HLA-DP SNPs and HCC susceptibility, a meta-analysis of studies published before January 2014 was carried out using the PubMed and Google Scholar databases. Odds ratios (ORs) and 95% confidence intervals (CI) were calculated for HLA-DP alleles, and for co-dominant, dominant, and recessive genotype models of each SNP, based on fixed- or random-effects models. A total of nine studies from six published articles were included. The association study between rs3077 and HCC susceptibility was performed in four independent comparisons that contained 1871 cases with hepatitis B virus (HBV)-related HCC and 3207 carriers with persistent HBV. Association between rs9277535 and HCC susceptibility was examined in five separate comparisons that contained 2017 cases and 3930 carriers. Our analysis indicated a significant association of rs3077 and rs9277535 with HCC susceptibility, suggesting that rs3077 might act beneficially against HCC susceptibility (A vs G: OR = 0.884, 95%CI = 0.803-0.973, P = 0.012; GA vs GG: OR = 0.842, 95%CI = 0.733-0.967, P = 0.015; AA+GA vs GG: OR = 0.848, 95%CI = 0.744-0.968, P = 0.014), and that rs9277535 might promote HCC susceptibility (AA vs GA: OR = 1.202, 95%CI = 1.011-1.428, P = 0.037). This study suggested that HLA-DP rs3077 and rs9277535 polymorphisms are associated with HCC susceptibility in the Asian population.

Modulating of ocular inflammation with macrophage migration inhibitory factor is associated with notch signalling in experimental autoimmune uveitis

The aim of this study was to examine whether macrophage migration inhibitory factor (MIF) could exaggerate inflammatory response in a mouse model of experimental autoimmune uveitis (EAU) and to explore the underlying mechanism. Mutant serotype 8 adeno-associated virus (AAV8) (Y733F)-chicken β-actin (CBA)-MIF or AAV8 (Y733F)-CBA-enhanced green fluorescent protein (eGFP) vector was delivered subretinally into B10.RIII mice, respectively. Three weeks after vector delivery, EAU was induced with a subcutaneous injection of a mixture of interphotoreceptor retinoid binding protein (IRBP) peptide with CFA. The levels of proinflammatory cytokines were detected by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Retinal function was evaluated with electroretinography (ERG). We found that the expression of MIF and its two receptors CD74 and CD44 was increased in the EAU mouse retina. Compared to AAV8.CBA.eGFP-injected and untreated EAU mice, the level of proinflammatory cytokines, the expression of Notch1, Notch4, delta-like ligand 4 (Dll4), Notch receptor intracellular domain (NICD) and hairy enhancer of split-1 (Hes-1) increased, but the ERG a- and b-wave amplitudes decreased in AAV8.CBA.MIF-injected EAU mice. The Notch inhibitor N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT) reduced the expression of NICD, Hes-1 and proinflammatory cytokines. Further, a MIF antagonist ISO-1 attenuated intraocular inflammation, and inhibited the differentiation of T helper type 1 (Th1) and Th17 in EAU mice. We demonstrated that over-expression of MIF exaggerated ocular inflammation, which was associated with the activation of the Notch signalling. The expression of both MIF and its receptors are elevated in EAU mice. Over-expression of MIF exaggerates ocular inflammation, and this exaggerated inflammation is associated with the activation of the Notch signalling and Notch pathway. Our data suggest that the MIF-Notch axis may play an important role in the pathogenesis of EAU. Both the MIF signalling pathways may be promising targets for developing novel therapeutic interventions for uveitis.

Spectroscopic study of Gd nanostructures quantum confined in Fe corrals

Low dimensional nanostructures have attracted attention due to their rich physical properties and potential applications. The essential factor for their functionality is their electronic properties, which can be modified by quantum confinement. Here the electronic states of Gd atom trapped in open Fe corrals on Ag(111) were studied via scanning tunneling spectroscopy. A single spectroscopic peak above the Fermi level is observed after Gd adatoms are trapped inside Fe corrals, while two peaks appear in empty corrals. The single peak position is close to the higher energy peak of the empty corrals. These findings, attributed to quantum confinement of the corrals and Gd structures trapped inside, are supported by tight-binding calculations. This demonstrates and provides insights into atom trapping in open corrals of various diameters, giving an alternative approach to modify the properties of nano-objects.

Codon usage bias analysis for the spermidine synthase gene from Camellia sinensis (L.) O. Kuntze

The spermidine synthase (SPDS) gene exists widely in all types of plants. In this paper, the codon usage of the SPDS gene from Camellia sinensis (CsSPDS) was analyzed. The results showed that the codon usage of the CsSPDS gene is biased towards the T-ended or A-ended codons, which is similar to that observed in 73 genes selected from the C. sinensis genome. An ENC-plot for 15 SPDS genes from various plant species suggested that mutational bias was the major factor in shaping codon usage in these genes. Codon usage frequency analysis indicated that there was little difference between the CsSPDS gene and dicot genomes, such as Arabidopsis thaliana and Nicotiana tabacum, but significant differences in codon usage were observed between the CsSPDS gene and monocot genomes, such as Triticum aestivum and Zea mays. Therefore, A. thaliana and N. tabacum expression systems may be more suitable for the expression of the CsSPDS gene.

A myeloablative conditioning regimen with fludarabine demonstrates good results in UCBT for 30 pediatric patients with hematologic malignancies, especially acute lymphoblastic leukemia

We retrospectively analyzed the safety and efficacy of a myeloablative conditioning regimen with fludarabine (FLU) in unrelated cord blood transplantation (UCBT) of 30 pediatric patients with hematologic malignancies. The conditioning regimen consisted of FLU, busulfan (BU) and cyclophosphamide (CY). All of the patients received Cyclosporine (CSA) and mycophenolate mofetil (MMF) as graft versus host disease (GVHD) prophylaxis. We achieved high engraftment rates (96.7%) and rapid hematopoietic reconstitution. Acute GVHD occurred in 12 cases of the 29 engraftment patients (41.4%), and 6 cases (20.7%) were of grade III-IV. Chronic GVHD only occurred in 1 of 28 evaluable patients (3.6%). Twenty-three patients (76.7%) became infected, and 3 cases (10.0%) died of severe infections. Cytomegalovirus (CMV) reactivation occurred in 70.0% of the patients, but no CMV diseases were observed, nor did any patients die of CMV infection. The cumulative incidence of relapse (6.7%) was significantly reduced, and none of the acute lymphoblastic leukemia (ALL) patients relapsed. The 3-year overall survival (OS) and event-free survival (EFS) rates were 73.3% and 70.0%, respectively. The 3-year OS and EFS of the ALL patients was 75.0%. This conditioning regimen demonstrates good results and security in UCBT, especially in acute lymphoblastic leukemia.

Fact versus artifact: avoiding erroneous estimates of sulfated glycosaminoglycan content using the dimethylmethylene blue colorimetric assay for tissue-engineered constructs

The 1,9-dimethylmethylene blue (DMMB) assay is widely used to quantify sulfated glycosaminoglycan (sGAG) contents of engineered tissues, culture media, tissue samples and bodily fluids, but the assay is subject to interference from polyanions such as hyaluronic acid (HA), DNA and RNA. We examined whether specific combinations of dye pH and absorbance wavelength could minimize non-sGAG artifacts without compromising DMMB assay sensitivity. HA and DNA solutions generated substantial signal at pH 3 but not at pH 1.5. Reducing dye pH did not significantly alter sGAG measurements for normal cartilage and meniscus tissues, but eliminated anomalously high apparent sGAG contents for enzymatically isolated chondrocytes, adipose-derived stem cell (ADSC)-agarose constructs and ADSC pellets. In a cartilage tissue-engineering case study, pH 3 dye indicated high apparent sGAG readings throughout culture in both basal and chondrogenic media, with a marked decline between day 14 and 21 for chondrogenic constructs. The pH 1.5 dye, however, indicated minimal sGAG accumulation in basal medium and stable sGAG content throughout culture in chondrogenic medium. As it is often difficult to know a priori whether all groups in a study will have sGAG contents high enough to overwhelm artifacts, we recommend modifying the standard DMMB assay to reduce the risk of spurious findings in tissue engineering and clinical research. Specifically, we recommend shifting to a pH 1.5 DMMB dye and basing quantification on the absorbance difference between 525 nm (µ peak) and 595 nm (β peak) to compensate for the moderate loss of sensitivity associated with reducing the dye pH.

Synaptic plasticity-related neural oscillations on hippocampus-prefrontal cortex pathway in depression

It is believed that phase synchronization facilitates neural communication and neural plasticity throughout the hippocampal-cortical network, and further supports cognition and memory. The pathway from the ventral hippocampus to the medial prefrontal cortex (mPFC) is thought to play a significant role in emotional memory processing. Therefore, the information transmission on the pathway was hypothesized to be disrupted in the depressive state, which could be related to its impaired synaptic plasticity. In this study, local field potentials (LFPs) from both ventral CA1 (vCA1) and mPFC were recorded in both normal and chronic unpredictable stress (CUS) model rats under urethane anesthesia. LFPs of all rats were recorded before and after the long-term potentiation (LTP) induced on the vCA1-mPFC pathway in order to figure out the correlation of oscillatory synchronization of LFPs and synaptic plasticity. Our results showed the vCA1-to-mPFC unidirectional phase coupling of the theta rhythm, rather than the power of either region, was significantly enhanced by LTP induction, with less enhancement in the CUS model rats compared to that in the normal rats. In addition, theta phase coupling was positively correlated with synaptic plasticity on vCA1-mPFC pathway. Moreover, the theta-slow gamma phase-amplitude coupling in vCA1 was long-term enhanced after high frequency stimulation. These results suggest that the impaired synaptic plasticity in vCA1-mPFC pathway could be reflected by the attenuated theta phase coupling and theta-gamma cross frequency coupling of LFPs in the depression state.

Erythropoietin promotes bone formation through EphrinB2/EphB4 signaling

Recent studies have demonstrated that erythropoietin (EPO) has extensive nonhematopoietic biological functions. However, little is known about how EPO regulates bone formation, although several studies suggested that EPO can affect bone homeostasis. In this study, we investigated the effects of EPO on the communication between osteoclasts and osteoblasts through the ephrinB2/EphB4 signaling pathway. We found that EPO slightly promotes osteoblastic differentiation with the increased expression of EphB4 in ST2 cells. However, EPO increased the expression of Nfatc1 and ephrinB2 but decreased the expression of Mmp9 in RAW264.7 cells, resulting in an increase of ephrinB2-expressing osteoclasts and a decrease in resorption activity. The stimulation of ephrinB2/EphB4 signaling via ephrinB2-Fc significantly promoted EPO-mediated osteoblastic differentiation in ST2 cells. EphB4 knockdown through EphB4 shRNA inhibited EPO-mediated osteoblastic phenotypes. Furthermore, in vivo assays clearly demonstrated that EPO efficiently induces new bone formation in the alveolar bone regeneration model. Taken together, these results suggest that ephrinB2/EphB4 signaling may play an important role in EPO-mediated bone formation.

Nitrogen-doped porous graphene–activated carbon composite derived from “bucky gels” for supercapacitors

Graphene-based “bucky gels” are used to prepare nitrogen-doped porous graphene–AC composite material for supercapacitors.

Correlation between DQB1 genetic polymorphism and genetic susceptibility in patients diagnosed with irritable bowel syndrome with diarrhea

We examined patients of Han nationality diagnosed with irritable bowel syndrome with diarrhea (IBS-D) in Guangdong, China, to analyze the correlation between DQB1 allele polymorphisms and the genetic susceptibility to IBS-D. A total of 120 IBS-D patients of Han nationality in Guangdong, China, and 60 healthy control volunteers were included. DQB1 allele polymorphisms were investigated by polymerase chain reaction. Subjects' serum interleukin (IL)-10 level, colonic permeability, and tight junction marker zonula occludens 1 (ZO1) mRNA level were also investigated. Our data showed that the DQB1*02 allele frequency was significantly higher in IBS-D patients, while the DQB1*0603 frequency was lower than in healthy volunteers. The DQB1*03, DQB1*04, DQB1*05, DQB1*0601, DQB1*0602, and DQB1*0604 alleles did not show significant differences between IBS-D patients and healthy controls. Furthermore, patients with DQB1*03- positive and DQB1*0603-negative alleles showed more severe colonic permeability and lower serum IL-10 level and ZO1 level compared to healthy controls or even IBS-D patients with other genotypes. The present study indicated the DQB1*02 or DQB1*0603 alleles are related to IBS-D occurrence in Guangdong, China, and the mechanism of the disease may be related to reduced serum IL-10 levels.

AdLTR2EF1α-FGF2-mediated prevention of fractionated irradiation-induced salivary hypofunction in swine

Patients frequently experience a loss of salivary function following irradiation (IR) for the treatment of an oral cavity and oropharyngeal cancer. Herein, we tested if transfer of fibroblast growth factor-2 (FGF2) cDNA could limit salivary dysfunction after fractionated IR (7.5 or 9 Gy for 5 consecutive days to one parotid gland) in the miniature pig (minipig). Parotid salivary flow rates steadily decreased by 16 weeks post-IR, whereas blood flow in the targeted parotid gland began to decrease ~3 days after beginning IR. By 2 weeks, post-IR salivary blood flow was reduced by 50%, at which point it remained stable for the remainder of the study. The single preadministration of a hybrid serotype 5 adenoviral vector encoding FGF2 (AdLTR2EF1a-FGF2) resulted in the protection of parotid microvascular endothelial cells from IR damage and significantly limited the decline of parotid salivary flow. Our results suggest that a local treatment directed at protecting salivary gland endothelial cells may be beneficial for patients undergoing IR for oral cavity and oropharyngeal cancer.