Synthesis, optical properties and theoretical modelling of discrete emitting states in doped silicon nanocrystals for bioimaging

The creation of multiple emission pathways in quantum dots (QDs) is an exciting prospect with fundamental interest and optoelectronic potential. For the first time, we report multiple emission pathways in semiconductor nanocrystals (NCs) where the number of emission pathways desired is controlled by the number of dopant atoms per quantum dot. The origin of additional emission pathways is explained by interactions between dopant states and NC energy levels. Density functional theory (DFT) calculations of undoped 2.3 nm silicon (Si NCs) and the same NCs doped with 2 interstitial Cu atoms show good agreement to experiment. Such calculations provide valuable data to explain the changes in optical transitions due to the Cu dopant in terms of transition energies, quantum yield and dopant position as a function of dopants per NC. Changes in the optical properties of Si NCs induced by dopant concentration include extended excitation range and enhanced absorption coefficients, emission redshifts of up to 60 nm, and a two-fold increase in quantum yields up to 22%. The optical properties of doped NCs lead to significant bioimaging improvements illustrated by in vitro cell imaging, including redshifted excitation wavelengths away from natural autofluorescence and enhanced fluorescent signals.

Disparate effects of antibiotics on hypertension

Gut microbiota are associated with a variety of complex polygenic diseases. The usage of broad-spectrum antibiotics by patients affected by such diseases is an important environmental factor to consider, because antibiotics, which are widely prescribed to curb pathological bacterial infections, also indiscriminately eliminate gut commensal microbiota. However, the extent to which antibiotics reshape gut microbiota and per se contribute to these complex diseases is understudied. Because genetics play an important role in predisposing individuals to these modern diseases, we hypothesize that the extent to which antibiotics influence complex diseases depends on the host genome and metagenome. The current study tests this hypothesis in the context of hypertension, which is a serious risk factor for cardiovascular diseases. A 3 × 2 factorial design was used to test the blood pressure (BP) and microbiotal effects of three different antibiotics, neomycin, minocycline, and vancomycin, on two well-known, preclinical, genetic models of hypertension, the Dahl salt-sensitive (S) rat and the spontaneously hypertensive rat (SHR), both of which develop hypertension, but for different genetic reasons. Regardless of the class, oral administration of antibiotics increased systolic blood pressure of the S rat, while minocycline and vancomycin, but not neomycin, lowered systolic blood pressure in the SHR. These disparate BP effects were accompanied by significant alterations in gut microbiota. Our study highlights the need to consider an individualized approach for the usage of antibiotics among hypertensives, as their BP could be affected differentially based on their individual genetic and microbiotal communities.

IL-37 inhibits IL-4/IL-13-induced CCL11 production and lung eosinophilia in murine allergic asthma

BACKGROUND

IL-37 is emerging as an anti-inflammatory cytokine, particularly in innate inflammation. However, the role of IL-37 in Th2-mediated allergic lung inflammation remains uncertain. We sought to determine the role and the underlying mechanisms of IL-37 in the development of house dust mites (HDM)-induced murine asthma model.

METHODS

We examined the effect of IL-37 administration during the sensitization or challenge phase on Th2-mediated allergic asthma induced by inhaled HDM. Cellular source of CCL11 and distribution of IL-37 receptors, IL-18Rα and IL-1R8, were determined in HDM-exposed lungs. Finally, we examined the effect of IL-37 on CCL11 production and STAT6 activation in different primary lung structural cell types upon IL-4/IL-13 stimulation.

RESULTS

IL-37 had no effect on HDM sensitization, but when administrated during the challenge phase, significantly attenuated pulmonary eosinophilia, CCL11 production, and airway hyper-reactivity (AHR). Interestingly, IL-37 treatment had no significant effects on lung infiltrating T cells and Th2 cytokine production. Intranasal co-administration of CCL11 reversed the inhibiting effect of IL-37 on HDM-induced pulmonary eosinophilia and AHR. Furthermore, we demonstrated that CCL11 was primarily expressed by fibroblasts and airway smooth muscle cells (AMSC), while IL-37 receptors by tracheobronchial epithelial cells (TEC). In vitro study showed that IL-37 inhibited IL-4/IL-13-induced STAT6 activation and CCL11 production by fibroblasts and AMSC, which was dependent on its direct action on TEC. Moreover, cell contact was required for the inhibitory effect of IL-37-treated TEC.

CONCLUSIONS

IL-37 attenuates HDM-induced asthma, possibly by inhibiting IL-4/IL-13-induced CCL11 production by fibroblasts and AMSC via its direct act on TEC.

[Effect of alprostadil on wound healing of scalded rats and the mechanism]

Objective: To explore effect of alprostadil on wound healing of scalded rats and the mechanism. Methods: According to random number table method, forty-eight Sprague Dawley rats were divided into sham scald group, simple scald group, lithium chloride group, and alprostadil group, with 12 rats in each group. Rats in sham injury group were sham injured on the back, and rats in the other three groups were inflicted with 30% total body surface area deep partial thickness scald on the back.Immediately after scald, rats in sham scald group and simple scald group were injected with 1 mL saline through caudal vein, and rats in lithium chloride group and alprostadil group were injected respectively with 1 mL lithium chloride and alprostadil through caudal vein. Saline, lithium chloride, and alprostadil were injected once in a day and lasted for 14 days. General wound appearance and wound healing rate on post scald day (PSD) 7, 10, 14 were observed and calculated. Expressions of protein and mRNA of Wnt1 and β-catenin on PSD 14 were detected. Data were processed with analysis of variance of factorial design, one-way analysis of variance, Student Newman Keuls q test, t test, and Bonferroni correction. Results: (1) On PSD 7, wounds of scalded rats in each group formed dry eschar and had little exudation. On PSD 10, wounds of rats in simple scald group were covered with eschar, with little exudation, and wounds of rats in lithium chloride group were covered with eschar, and partial wounds healed under the eschar. On PSD 10, partial eschar of rats in alprostadil group desquamated; partial wounds healed; newly burned skin was ruddy. On PSD 14, partial wounds of rats in simple scald group were healed under eschar with little exudation. On PSD 14, most of the eschar of rats in lithium chloride group were desquamated with patial wounds healed and little exudation. On PSD 14, wounds of rats in alprostadil group were basically healed with vigorously growing hair on the back. (2) On PSD 7, the wound healing rates of rats in simple scald group, lithium chloride group, and alprostadil group were close (F=0.41, P>0.05). On PSD 10 and 14, wound healing rate of rats in lithium chloride group and alprostadil group were significantly higher than that in simple scald group (q=5.73, 17.45, 26.30, 11.28, P<0.05), and wound healing rate of rats in alprostadil group was significantly higher than that in lithium chloride group (q=32.03, 28.73, P<0.05). (3) On PSD 14, the mRNA expressions of Wnt1 and β-catenin of rats in lithium chloride group and alprostadil group were significantly higher than those in simple scald group (q=65.40, 19.16, 66.79, 18.41, P<0.05), and the mRNA expressions of Wnt1 and β-catenin of rats in simple scald group was significantly higher than those in sham scald group (t=14.86, 4.46, P<0.05). (4) On PSD 14, the protein expressions of Wnt1 and β-catenin of rats in lithium chloride group and alprostadil group were 0.98±0.05, 0.98±0.06, 0.97±0.06, and 1.00±0.06, which were significantly higher than 0.49±0.04 and 0.66±0.04 of rats in simple scald group (q=34.62, 22.38, 33.61, 23.47, P<0.05). On PSD 14, the protein expressions of Wnt1 and β-catenin of rats in simple scald group was significantly higher than 0.29±0.03 and 0.31±0.03 of rats in sham scald group (q=14.73, 23.88, P<0.05). Conclusions: Alprostadil can accelerate wound healing through activating Wnt/β-catenin signal pathway and upregulating the expressions of Wnt1 and β-catenin.

Discovery of 4 exonic and 1 intergenic novel susceptibility loci for leprosy

Seven new risk coding variants have been identified through an exome-wide association study (EWAS), which studied the contributions of protein-coding variants to leprosy susceptibility. But some potential susceptibility loci were not studied in the previous EWAS study because of the project consideration. Seventeen unstudied potential susceptibility loci of the previous EWAS were validated in 3169 cases and 9814 controls in this study. Four disease-associated exonic loci were identified: rs671 in ALDH2 (P = 2.0 × 10^-20 , odds ratio [OR] = 1.35), rs13259978 in SLC7A2 (P = 1.74 × 10^-8 , OR = 1.28), rs925368 in GIT2 (P = 9.18 × 10^-17 , OR = 1.44), and rs75680863 in TCN2 (P = 8.37 × 10^-21 , OR = 0.74). Potentially implicating ZFP36L1 as a new susceptibility gene, 1 intergenic single nucleotide polymorphism (SNP), rs1465788 (P = 7.81 × 10^-6 , OR = 0.88), was also suggested to be associated with leprosy. A luciferase reporter assay showed that the rs1465788 risk allele notably decreased the transcription activity of the flanking sequence. These findings suggest the possible involvement of lipid metabolism, NF-κB homeostasis and macrophage antimicrobial pathways in leprosy pathogenesis.

Comparison of heat transfer models with databank of supercritical fluid

Because of the large variation of thermal–physical properties near pseudo-critical point, heat transfer of supercritical water shows abnormal behavior. Thus, an accurate prediction of heat transfer between the cladding and fluid plays a very important role. It is necessary to investigate the reliably of heat transfer models in the vicinity of the pseudo-critical point. In the frame of evaluating the present HT models and developing new reliable prediction models, databank of heat transfer of supercritical water flowing in tube were established by Karlsruhe Institute of Technology (KIT) with more than 35,000 experimental data. A thorough analysis and assessment was carried out, to give an insight into the characters of the database. Experimental data from different sources are compared to figure out the deviation between different sources and to present the reliability of the database.

Mechanistic prediction of post dryout heat transfer and rewetting

Post dryout heat transfer and rewetting are important processes determining the level and the time duration of high temperature phase and the integrity of the fuel cladding. In spite of extensive studies in the past decades, reliable prediction methods are still missing due to the complexity of processes involved, which consist mainly of interaction between solid wall, main gas flow and droplets. In the present study, a phenomenological model is proposed considering the three individual heat transfer processes between the three parts. Main new features of the present model compared to the models available in the open literature are the mechanistic modeling of (a) droplet concentration and droplet size, (b) turbulent fluctuation velocity of droplets and its critical value, (c) evaporation rate of droplets arriving the wall. Comparison of the new model with selected experimental data shows at least qualitatively good agreement. The experimental behavior of wall temperature can be well explained. According to the new model the Leidenfrost effect results in the hysteresis behavior of wall temperature.

Neuronal nitric oxide synthase inhibition reduces brain damage by promoting collateral recruitment in a cerebral hypoxia-ischemia mice model

OBJECTIVE

The collateral circulation development is considered as a compensatory inherent mechanism to restore damaged blood perfusion after ischemia. We aimed to detect the collateral flow and the mean blood-flow velocities (mBFVs) level in the basilar trunk during or after cerebral hypoxia-ischemia in the mice brain and explore the effect of neuronal nitric oxide synthase (nNOS) inhibition on the collateral flow.

MATERIALS AND METHODS

C57BL/6J mice and the nNOS knockout (KO) mice were randomly divided into a sham-operated group (control) and the hypoxia-ischemia (HI) groups that were treated with the phosphate buffered solution (PBS) control or 7-nitroindazole (7-NI). Cortexes were harvested after the HI treatment for analysis of nNOS expression using Western blot and reverse transcription-polymerase chain reaction (RT-PCR). Ultrasound imaging experiments were performed to detect the collateral flow and the mBFVs level in the basilar trunk.

RESULTS

After cerebral HI, the cortical nNOS mRNA and protein levels increased markedly compared with the sham-operated control mice. Besides, 7-NI treatment had no effect on the blood flow in the sham-operated control mice. What's more, either the 7-NI pretreatment or the nNOS gene knockdown before the HI procedure could attenuate the brain injury by the increased collateral flow and the decreased mBFVs level in the basilar trunk.

CONCLUSIONS

nNOS inhibition protected hypoxic-ischemic-induced mice brain damage by the increased collateral flow and the decreased mBFVs level in the basilar trunk. Therefore, the 7-NI administration may have potential utility for the treatment of HI injury in human beings.

RPYFMM: Parallel Adaptive Fast Multipole Method for Rotne-Prager-Yamakawa Tensor in Biomolecular Hydrodynamics Simulations

RPYFMM is a software package for the efficient evaluation of the potential field governed by the Rotne-Prager-Yamakawa (RPY) tensor interactions in biomolecular hydrodynamics simulations. In our algorithm, the RPY tensor is decomposed as a linear combination of four Laplace interactions, each of which is evaluated using the adaptive fast multipole method (FMM) [1] where the exponential expansions are applied to diagonalize the multipole-to-local translation operators. RPYFMM offers a unified execution on both shared and distributed memory computers by leveraging the DASHMM library [2, 3]. Preliminary numerical results show that the interactions for a molecular system of 15 million particles (beads) can be computed within one second on a Cray XC30 cluster using 12, 288 cores, while achieving approximately 54% strong-scaling efficiency.

All-polymer fiber-optic pH sensor

A novel all-polymer fiber-optic pH sensor using a UV-cured pH-sensitive hydrogel, poly(ethylene glycol) diacrylate (PEGDA), coated on a polymer fiber Bragg grating was developed. The PEGDA increased in volume according to the pH value of the surrounding fluid, which subsequently induced a lateral stress in the polymer fiber Bragg grating. The proposed pH sensor exhibits a pH sensitivity of up to -0.41 nm/pH and a fast response time of 30 s.

Prospective plasma efavirenz concentration assessment in Chinese HIV-infected adults enrolled in a large multicentre study

OBJECTIVES

Few studies have explored the optimal dosing for efavirenz in individuals from China. We investigated plasma efavirenz concentrations and their association with efficacy and tolerance of efavirenz 600 mg daily in Chinese HIV-infected adults.

METHODS

An analysis was performed using plasma samples from 455 patients enrolled in a prospective multicentre trial in China. A total of 1198 plasma samples collected at weeks 4, 24 and 48 following antiretroviral therapy initiation were analysed. The mid-dose interval efavirenz concentrations (C12 ) were determined using high-performance liquid chromatography.

RESULTS

The median efavirenz concentration (interquartile range) steadily increased over time from 3.02 (2.28-4.23) to 3.71 (2.91-4.91) mg/L from week 4 to 48 (P < 0.001). The proportion of patients with C12 > 4.0 mg/L also rose from 28.0% to 34.2% and 43.8%, measured at 4, 24 and 48 weeks, respectively (P < 0.001). Five patients had efavirenz concentrations < 1.0 mg/L at week 4, 24 or 48. In the multivariable regression analysis, lower body weight and non-Han ethnicities were associated with higher efavirenz concentrations over time. At each time-point, patients with a body weight < 60 kg had significantly higher efavirenz C12 compared with those with body weight ≥ 60 kg (P < 0.05).

CONCLUSIONS

Efavirenz concentrations increased steadily over 48 weeks, and a substantial proportion of participants had efavirenz C12 above the upper limit of the proposed therapeutic window, especially those with low body weight (< 60 kg). Based upon these findings, a dosage reduction of efavirenz to 400 mg daily may warrant consideration in this population, especially for those with lower body weight.

The optimal anatomic site for a single slice to estimate the total volume of visceral adipose tissue by using the quantitative computed tomography (QCT) in Chinese population

BACKGROUND/OBJECTIVES

To investigate the relationship between the cross-sectional visceral adipose tissue (VAT) areas at different anatomic sites and the total VAT volume in a healthy Chinese population using quantitative computed tomography (QCT), and to identify the optimal anatomic site for a single slice to estimate the total VAT volume.

SUBJECTS/METHODS

A total of 389 healthy Chinese subjects aged 19-63 years underwent lumbar spine QCT scans. The cross-sectional area of total adipose tissue and VAT were measured using the tissue composition module of the software (QCT Pro, Mindways) at each intervertebral disc level from T₁₂/L₁ to L₅/S₁, as well as at the umbilical level. The total VAT volume was defined as the fat areas multiplied by the height of vertebral body for all six slices. Statistical analysis was performed to determine the correlation between single-slice VAT areas and the total VAT volume. Moreover, the optimal anatomic site for a single slice to estimate the total VAT volume was identified by multiple regression analysis.

RESULTS

The cross-sectional area of VAT and subcutaneous adipose tissue (SAT) measured at each anatomic site was all highly correlated with the total VAT volume and the total SAT volume (r = 0.89-0.98). Additionally, the VAT area measured at the L₂/L₃ level showed the strongest correlation with the total VAT volume (r = 0.98, P < 0.001). Covariates including age, gender, BMI, waist, and hypertension make a slight effect on the prediction of the total VAT volume.

CONCLUSION

It is feasible to perform measurements of VAT area on a single slice at L₂/L₃ level for estimating the total VAT volume.

Period Increase and Amplitude Distribution of Kink Oscillation of Coronal Loop

Coronal loops exist ubiquitously in the solar atmosphere. These loops puzzle astronomers over half a century. Solar magneto-seismology (SMS) provides a unique way to constrain the physical parameters of coronal loops. Here, we study the evolution of oscillations of a coronal loop observed by the Atmospheric Imaging Assembly (AIA). We measure geometric and physical parameters of the loop oscillations. In particular, we find that the mean period of the oscillations increased from 1048 to 1264 s during three oscillatory cycles. We employ the differential emission measure method and apply the tools of SMS. The evolution of densities inside and outside the loop is analyzed. We found that an increase of density inside the loop and decrease of the magnetic field strength along the loop are the main reasons for the increase in the period during the oscillations. Besides, we also found that the amplitude profile of the loop is different from a profile would it be a homogeneous loop. It is proposed that the distribution of magnetic strength along the loop rather than density stratification is responsible for this deviation. The variation in period and distribution of amplitude provide, in terms of SMS, a new and unprecedented insight into coronal loop diagnostics.

[Clinical significance of targeting drug-based molecular biomarkers expression in ovarian clear cell carcinoma]

Objective: To assess the expression level of targeting drug-based molecular biomarkers in ovarian clear cell carcinoma (OCCC) tissues and its clinical significance. Methods: A total of 63 OCCC patients included 40 primary OCCC and 23 recurrent OCCC for secondary cytoreductive surgery (SCS), who had received primary surgeries at Fudan University Shanghai Cancer Center between January, 2008 and December, 2015 were enrolled, and immunohistochemistry SP method was used to test human epidermal growth factor receptor (EGFR), human epidermal growth factor receptor-2 (HER2), aurora kinase A (AURKA), breast cancer susceptibility gene 1 (BRCA1), BRCA2 and programmed death-ligand 1 (PD-L1)protein expression in paraffin-embedded tissues. Results: The positive rates of EGFR, HER2, AURKA,BRCA1, BRCA2 and PD-L1 in primary and recurrent tumor tissues were respectively 20% (8/40) vs 30% (7/23) , 22% (9/40) vs 35% (8/23) , 38% (15/40) vs 35% (8/23) , 42% (17/40) vs 39% (9/23) , 20% (8/40) vs 22% (5/23) , 25% (10/40) vs 17% (4/23) , and there were no significant differences between primary and recurrent OCCC (all P>0.05). χ(2)-test or Fisher exact analysis revealed that HER2 expression in recurrent tumor tissues had a relationship with chemoresistance (P<0.05), while the expression of other biomarkers showed no significant relationship with chemoresistance (all P>0.05). Further, Kaplan-Meier survival analysis showed that patients with HER2 and AURKA-positive expression had a significantly shorter progression-free survival time in primary OCCC (4 months vs 10 months, log-rank test, P<0.05 for HER2; and 4 months vs 10 months, P<0.05 for AURKA); and a shorter overall survival time after SCS in recurrent OCCC (10 months vs 44 months, P<0.05 for HER2; and 13 months vs 43 months, P<0.05 for AURKA). However, multivariate Cox proportional hazards regression analysis indicated that none of these 6 biomarkers was independent risk factor of progression-free survival time of primary OCCC or overall survival time after SCS for recurrent OCCC (P>0.05). Conclusion: HER2 and AURKA could serve as prognostic factors in ovarian clear cell carcinoma.

Effects of coexisting BDE-47 on the migration and biodegradation of BDE-99 in river-based aquifer media recharged with reclaimed water

Two prominent polybrominated diphenyl ether (PBDE) congeners have been included in the persistent organic pollutant list, 2,2',4,4',5-tetrabromodiphenyl ether (BDE-99) and 2,2,4,4'-tetrabromodiphenyl ether (BDE-47), which have been detected in treated municipal wastewater, river water, and sediments in China. A lab-scale column experiment was established to investigate the effects of the competitive sorption of BDE-47 on BDE-99 biodegradation and migration in two types of river-based aquifer soils during groundwater recharge with reclaimed water. Two types of recharge columns were used, filled with either silty clay (SC) or black carbon-amended silty clay (BCA). The decay rate constants of BDE-99 in the BCA and SC systems were 0.186 and 0.13 m^-1 in the single-solute system and 0.128 and 0.071 m^-1 in the binary-solute system, respectively, showing that the decay of BDE-99 was inhibited by the coexistence of BDE-47. This was particularly evident in the SC system because the higher hydrophobicity of BDE-99 determined the higher affinity and competition for sorption sites onto black carbon. The biodegradation of BDE-99 was suppressed by the coexistence of BDE-47, especially in the SC system. Lesser-brominated congeners (BDE-47 and BDE-28) and higher-brominated congeners (BDE-100, BDE-153, BDE-154, and BDE-183) were generated in the four recharge systems, albeit at different ratios. Bacterial biodiversity was influenced by the presence of BDE-47 in the SC system, while it had no significant effect on the BCA system, because the high sorption capacity of black carbon on the hydrophobic PBDEs effectively reduced their toxicity. The ranking order of the most abundant classes changed markedly due to the coexistence of BDE-47 in both the SC and BCA systems. The ranking order of the most abundant genera changed from Azospira, Methylotenera, Desulfovibrio, Methylibium, and Bradyrhizobium to Halomonas, Hyphomicrobium, Pseudomonas, Methylophaga, and Shewanella, which could be involved in PBDE degradation.