Giant isotope effect on phonon dispersion and thermal conductivity in methylammonium lead iodide

Lead halide perovskites are strong candidates for high-performance low-cost photovoltaics, light emission, and detection applications. A hot-phonon bottleneck effect significantly extends the cooling time of hot charge carriers, which thermalize through carrier-optic phonon scattering, followed by optic phonon decay to acoustic phonons and finally thermal conduction. To understand these processes, we adjust the lattice dynamics independently of electronics by changing isotopes. We show that doubling the mass of hydrogen in methylammonium lead iodide by replacing protons with deuterons causes a large 20 to 50% softening of the longitudinal acoustic phonons near zone boundaries, reduces thermal conductivity by ~50%, and slows carrier relaxation kinetics. Phonon softening is attributed to anticrossing with the slowed libration modes of the deuterated molecules and the reduced thermal conductivity to lowered phonon velocities. Our results reveal how tuning the organic molecule dynamics enables control of phonons important to thermal conductivity and the hot-phonon bottleneck.

Effect of abduction on avascular necrosis of the femoral epiphysis in patients with late-detected developmental dysplasia of the hip treated by closed reduction: a MRI study of 59 hips

PURPOSE

The purpose of this study was to explore whether increasing the hip abduction angle would increase the incidence of avascular necrosis (AVN) in patients with late- detected developmental dysplasia of the hip (DDH) treated by closed reduction (CR) and spica cast immobilization.

METHODS

A total of 55 patients (59 hips) with late-detected DDH underwent MRI after CR. Hip abduction angle and hip joint distance were measured on postoperative MRI transverse sections. The acetabular index and centre-edge angle were measured on plain radiographs at the last follow-up. The presence of AVN according to Kalamchi and McEwen's classification was assessed. We retrospectively analyzed the associations among abduction angles, hip joint distances, radiographic parameters, AVN and final outcomes, exploring the relationship between hip joint abduction angle and AVN rate.

RESULTS

The mean age at the time of CR was 14.4 months SD 5.5 (6 to 28), and the mean follow-up was 26.2 months SD 8.1 (12.4 to 41.7). The mean hip abduction angle was 70.2° SD 7.2° (53° to 85°) on the dislocated side and 63.7° SD 8.8° (40° to 82°) on the normal side; the mean hip joint distance was 5.1 mm SD 1.9 (1.3 to 9.1) on the dislocated side and 2.2 mm SD 0.6 on the normal side (1.3 to 3.3). Eight of 59 hips (13.6%) developed AVN. Neither the amount of abduction nor hip joint distance increased the AVN rate (p = 0.97 and p = 0.65, respectively) or the dislocation rate (p = 0.38 and p = 0.14, respectively).

CONCLUSION

Abduction angle up to 70.2° following CR did not increase the AVN rate in children aged six to 28 months with late-detected DDH treated by CR.

LEVEL OF EVIDENCE

III.

[Construction of prognostic model and identification of prognostic biomarkers based on the expression of long non-coding RNA in bladder cancer via bioinformatics]

OBJECTIVE

To construct the prognostic model and identify the prognostic biomarkers based on long non-coding RNA (lncRNA) in bladder cancer.

METHODS

The lncRNA expression data and corresponding clinical data of bladder cancer were collected from The Cancer Genome Atlas (TCGA) database. The software Perl and R, and R packages were used for data integration, extraction, analysis and visualization. Detailly, R package "edgeR" was utilized to screen differentially expressed lncRNA in bladder cancer tissues compared with the normal bladder samples. The univariate Cox regression and the least absolute shrinkage and selection operator (Lasso) regression were performed to identify key lncRNA that were utilized to construct the prognostic model by the multivariate Cox regression. According to the median value of the risk score, all patients were divided into the high-risk group and low-risk group to perform the Kaplan-Meier (K-M) survival curves, receiver operating characteristic (ROC) curve and C-index, estimating the prognostic power of the prognostic model. In addition, the hazard ratio (HR) and 95% confidence interval (CI) of each key lncRNA were also calculated by the multivariate Cox regression. Moreover, we performed the K-M survival analysis for each significant key lncRNA from the result of the multivariate Cox regression.

RESULTS

A total of 691 lncRNA were identified as differentially expressed lncRNA, and 35 lncRNA signatures were initially considered associated with the prognosis of bladder cancer, where in 23 lncRNA were identified as key lncRNA associated with the prognosis. The overall survival time in years of the low-risk group was obviously longer than that of the high-risk group [(2.85±2.72) years vs. (1.58±1.51) years, P<0.001]. The area under the ROC curve (AUC) was 0.813 (3-year survival) and 0.778 (5-year survival) respectively, and the C-index was 0.73. In addition, HR and 95%CI of each key lncRNA were calculated by the multivariate Cox regression and 11 lncRNA were significant. Furthermore, K-M survival analysis revealed the independent prognostic value of 3 lncRNA, including AL589765.1 (P=0.004), AC023824.1 (P=0.022)and PKN2-AS1 (P=0.016).

CONCLUSION

The present study successfully constructed the prognostic model based on the expression level of 23 lncRNA and finally identified one protective prognostic biomarker AL589765.1, and two adverse prognostic biomarkers including AC023824.1 and PKN2-AS1 in bladder cancer.

[Analysis of intratesticular condition in micro-dissection testicular sperm extraction era]

OBJECTIVE

To summarizes the intratesticular condition of azoospermia patients, to understand azoospermia more intuitively, and improve the ability of clinical doctors to predict the success rate of microsperm extraction in azoospermia patients.

METHODS

Azoospermia patients (excluding Klinefelter's syndrome) who underwent a micro-TESE during January 2014 and January 2018 in a single center were enrolled. The types of seminiferous tubules were summarized, and the clinical characteristics of different types of seminiferous tubules compared with the success rates of sperm extraction. In this study, 472 cases of non-obstructive azoospermia (excluding Klinefelter's syndrome) were analyzed by SPSS 21.0 software package. Relevant data were expressed by median(minimum,maximum).t-test was used to compare the difference of success rate of sperm extraction between each group and the group with the lowest rate (a type).

RESULTS

The 472 patients with non-obstructive azoospermia underwent micro-TESE. The mean age of the patients was 31 (23, 46) years, the mean testicular size was 10 (1, 20) mL, the mean FSH was 15.4 (1.21, 68.4) IU/L, the mean T was 8.34 (0.69, 30.2) nmol/L, and totally 202 patients achieved success in micro-TESE (42.7%, 202/472). According to the seminiferous tubules seen during the operation, they were divided into the following six types: Class a, seminiferous tubules developed well and uniformly; Class b, seminiferous tubules developed well, occasionally slightly thick; Class c, seminiferous tubules were generally thin; Class d, seminiferous tubules basically atrophied, occasionally well-developed seminiferous tubules; Class e, all seminiferous tubules atrophied; Class f, seminiferous tubules were infiltrated by yellow substances. The success rate of micro-TESE varied greatly among different types of the patients. A total of 78 patients with type a were 29 (24, 40) years old, FSH 11.1 (1.21, 15.8) IU/L, T 10.2 (3.29, 26.5) nmol/L), and testicular size 12 (12, 20) mL. The successful rate of sperm extraction was 6.41%; 82 patients with type b were 31 (23, 42) years old, FSH 13.8 (3.23, 19.6) IU/L, T 9.44 (3.58, 30.2) nmol/L), and testicular size 12(8,15) mL. The successful rate of sperm extraction was 74.39%; There were 162 patients in group c, aged 31 (25, 40), FSH 19.6 (9.28, 26.6) IU/L, T 8.75 (5.66, 18.6) nmol/L, and testicular size 8 (5, 12) mL. The successful rate of sperm extraction was 45.06%. There were 36 patients in group d, aged 25 (23,38) years and FSH 28.5 (19.3, 45.6) IU/L, T 6.52 (2.12, 9.83) nmol/L, and testicular size 5 (3, 8) mL, and the success rate of sperm extraction was 94.44%. 26 patients with type e were 28(23, 46) years old, FSH 31.3 (18.5, 68.4) IU/L, T 6.72 (0.69, 18.2) nmol/L, and testicular size 5 (1, 8) mL. The success rate of sperm extraction was 45.38%. 88 patients with type f were 29 (24, 38) years old, FSH 18.5 (5.23, 31.6) IU / L, T 8.32 (3.58, 16.5) nmol/L, and testicular size 12 (6, 20) mL. The success rate of sperm extraction was 28.41%.

CONCLUSION

The success rate of micro-TESE in different types of seminiferous tubules in testis can be helpful to the judgement of the surgeon during the operation.

Therapeutic effects of probiotic Clostridium butyricum WZ001 on bacterial vaginosis in mice

AIMS

To observe the therapeutic effects of vaginal infusion of probiotic Clostridium butyricum WZ001 on bacterial vaginosis (BV) in mice.

METHODS AND RESULTS

Female ICR mice were used to establish the model of BV by infecting oestrogen-treated mice with Escherichia coli, and then treated with high- and low dose of C. butyricum. Clinical indexes of mice in the C. butyricum-treated groups were significantly improved and comparable to those in the antibiotic group. Pap staining showed that neutrophil count was significantly increased after modelling and largely decreased after C. butyricum treatment (P < 0·01). Dynamic observation of E. coli and Lactobacillus showed that the number of E. coli significantly decreased in the C. butyricum-treated groups or in the antibiotic group with prolonged treatment (P < 0·01). Besides, the number of E. coli in the low-dose C. butyricum group was higher than that in either its high-dose counterpart or the antibiotic group respectively (P < 0·01). The number of Lactobacillus decreased evidently in the antibiotic group (P < 0·01), while that in the C. butyricum groups remained consistent. Moreover, C. butyricum inhibited the proliferation of E. coli by the experiment in vitro. The phosphorylation of nuclear factor-kappa B (NF-κB) p65 in vaginal tissue and the serum levels of inflammatory cytokines, IL-1β, TNF-α and IL-6, increased after modelling and significantly decreased after treated with C. butyricum (P < 0·01), with no difference found when compared with the antibiotic group.

CONCLUSION

Clostridium butyricum inhibits the growth of pathogenic bacteria as well as the inflammatory response induced by E. coli and promotes the growth of Lactobacillus to maintain the vaginal micro-ecological balance.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results suggest that probiobitc C. butyricum WZ001 has a great potential in the clinical treatment of BV.

Dynamic properties of different liquid states in systems with competing interactions studied with lysozyme solutions

Recent studies of colloidal systems with a short-range attraction and long-range repulsion (SALR) have been demonstrated to have a generalized phase diagram with multiple liquid states defined by their structures. In this paper, we identify the different liquid states of previous experimentally studied lysozyme samples within this proposed generalized state diagram and explore the dynamic properties of each liquid state. We show that most lysozyme samples studied here and previously at low and intermediate concentrations are dispersed fluids while a few high concentration samples are randomly percolated liquids. In the dispersed fluid region, the short-time diffusion coefficient measured by neutron spin echo agrees well with the long time diffusion coefficient estimated with the solution viscosity. This dynamic feature is maintained even for some samples in the random percolated region. However, the short-time and long-time diffusion coefficients of random percolated fluids deviate at larger concentration and attraction strength. At high enough concentrations, the mean square displacement can be as slow as those of many glassy colloidal systems at time scales near the characteristic diffusion time even though these lysozyme samples remain in liquid states at the long-time limit. We thus identify the region in the generalized phase diagram where these equilibrium states with extremely slow local dynamics exist relative to bulk percolation and kinetic arrest (gel and glassy) transitions.

[Relationship between FGF23/FGFR4 expression in atrial tissue and atrial fibrosis in patients with atrial fibrillation]

Objective: To observe the expression of fibroblast growth factor 23 (FGF23) and FGFR4 in patients with atrial fibrillation (AF) and its relationship with atrial fibrosis. Methods: Fifty-one patients with rheumatic heart disease undergoing cardiac surgery at the Second Affiliated Hospital of Nanchang University from October 2016 to April 2017 were divided into two groups according to whether they were complicated with atrial fibrillation: 39 patients with persistent AF(AF group), and 12 patients with sinus rhythm (SR group). The right atrial appendage was cut out during cardiac surgery. The expression of FGF23 and FGFR4 mRNA was detected by quantitative real-time PCR. The expression of FGFR4 protein was detected by Western blot. Atrial structure was evaluated by echocardiography. Masson staining was used to evaluate the degree of atrial fibrosis. The expression of FGF23 and FGFR4 was compared between the two groups.Additionally, the relationship between FGF23 and FGFR4 expression and atrial fibrosis was evaluated. Results: AF group had significantly higher right and left atrial diameter than SR group((40.1±1.6 )mm vs (34.1±1.5)mm, (52.4±2.9)mm vs (41.3±2.4)mm, all P<0.05) . There were no statistically significant differences in age, gender, ejection fraction between the two groups. The expression of FGF23 and FGFR4 mRNA in AF group were significantly higher than those in SR group (1.93±0.32 vs 0.93±0.14, 1.89±0.17 vs 0.91±0.11, both P<0.05). Compared with the SR group, the protein expression of FGFR4 in the AF group was significantly higher(1.76±0.21 vs 0.84±0.12). In AF group, there was no correlation between FGF23 mRNA and atrial diameter (r=0.274 (left atrial), r=0.238 (right atrium), both P>0.05). Meanwhile, FGFR4 mRNA and protein expression had no correlation with atrial diameter either. There was positive correlation between FGF23 mRNA and atrial collagen volume fraction in AF group (r=0.42, P<0.05). The expression of FGFR4 mRNA and protein were positively correlated with the atrial collagen volume fraction (r=0.573, r=0.478, all P<0.05). Conclusion: The expression of FGF23 and FGFR4 in atrial fibrillation patients is increased, which is positively correlated with atrial fibrosis, suggesting that FGF23/FGFR4 pathway may play an important role in atrial fibrillation by promoting atrial fibrosis.