Determination of secretory granule maturation times in pancreatic islet β-cells by serial block-face electron microscopy

It is shown how serial block-face electron microscopy (SBEM) of insulin-secreting β-cells in wild-type mouse pancreatic islets of Langerhans can be used to determine maturation times of secretory granules. Although SBEM captures the β-cell structure at a snapshot in time, the observed ultrastructure can be considered representative of a dynamic equilibrium state of the cells since the pancreatic islets are maintained in culture in approximate homeostasis. It was found that 7.2 ± 1.2% (±st. dev.) of the β-cell volume is composed of secretory granule dense-cores exhibiting angular shapes surrounded by wide (typically ≳100 nm) electron-lucent halos. These organelles are identified as mature granules that store insulin for regulated release through the plasma membrane, with a release time of 96 ± 12 h, as previously obtained from pulsed ³⁵S-radiolabeling of cysteine and methionine. Analysis of β-cell 3D volumes reveals a subpopulation of secretory organelles without electron-lucent halos, identified as immature secretory granules. Another subpopulation of secretory granules is found with thin (typically ≲30 nm) electron-lucent halos, which are attributed to immature granules that are transforming from proinsulin to insulin by action of prohormone convertases. From the volume ratio of proinsulin in the immature granules to insulin in the mature granules, we estimate that the newly formed immature granules remain in morphologically-defined immature states for an average time of 135 ± 14 min, and the immature transforming granules for an average time of 130 ± 17 min.

High-Statistics Measurement of Neutrino Quasielasticlike Scattering at 6 GeV on a Hydrocarbon Target

We measure neutrino charged-current quasielasticlike scattering on hydrocarbon at high statistics using the wideband Neutrinos at the Main Injector beam with neutrino energy peaked at 6 GeV. The double-differential cross section is reported in terms of muon longitudinal (p_{∥}) and transverse (p_{⊥}) momentum. Cross section contours versus lepton momentum components are approximately described by a conventional generator-based simulation, however, discrepancies are observed for transverse momenta above 0.5  GeV/c for longitudinal momentum ranges 3-5 and 9-20  GeV/c. The single differential cross section versus momentum transfer squared (dσ/dQ_{QE}^{2}) is measured over a four-decade range of Q^{2} that extends to 10  GeV^{2}. The cross section turnover and falloff in the Q^{2} range 0.3-10  GeV^{2} is not fully reproduced by generator predictions that rely on dipole form factors. Our measurement probes the axial-vector content of the hadronic current and complements the electromagnetic form factor data obtained using electron-nucleon elastic scattering. These results help oscillation experiments because they probe the importance of various correlations and final-state interaction effects within the nucleus, which have different effects on the visible energy in detectors.

[Develop the active surveillance system for vaccine safety in China]

Post-marketing surveillance of vaccine safety is an important measure to detect adverse events following immunization and therefore reduce the harms to public health. The conventional method for safety surveillance is a passive way through spontaneous reporting, which suffer from under-reporting and incomplete. While active surveillance, a newly proposed surveillance method in developed countries, is capable to make up the deficiencies of passive surveillance. The surveillance system of vaccine safety in China is currently using passive surveillance, and facing many problems and challenges. This arouses a need to promote development of an active surveillance system for vaccine safety in China, learning from the experience world-wide. This commentary aims to throw out suggestions for establishing the active surveillance system, according to the specific situation in China and based on a scoping review of literature.

Degradation of antibiotics in multi-component systems with novel ternary AgBr/Ag3PO4@natural hematite heterojunction photocatalyst under simulated solar light

Abatement of antibiotics from aquatic systems is of great importance but remains a challenge. Herein, we prepared ternary AgBr/Ag₃PO₄@natural hematite (AgBr/Ag₃PO₄@NH) heterojunction composite via a simple route for the photocatalytic degradation of antibiotic pollutants. By adjusting the dose of Ag species, four products with different Ag content (denoted as Ag_0.5BrPFe, Ag₁BrPFe, Ag_1.5BrPFe, and Ag₂BrPFe) were developed. Among them, Ag_1.5BrPFe exhibited the best photocatalytic activity. Four antibiotics (i.e. ciprofloxacin (CIP), norfloxacin (NOR), sulfadiazine (SDZ), and tetracycline (TTC)) could be degraded with synthesized Ag_1.5BrPFe in multi-component systems. Water matrix indexes including solution pH, coexisting anions, humic acids exhibited distinct effects on the degradation process. The results revealed that the degradation process was accelerated at acidic conditions while depressed at basic conditions. Superoxide radical and hole were detected by in situ electron spin resonance technique and played the dominant roles. The degradation pathway TTC was tentatively established followed with the identification of the degradation intermediates and computational analysis. This work would shed light on the photocatalytic degradation mechanism of organic pollutants by the AgBr/Ag₃PO₄@NH composite.

Publisher's Note: Identification of Nuclear Effects in Neutrino-Carbon Interactions at Low Three-Momentum Transfer [Phys. Rev. Lett. 116, 071802 (2016)]

This corrects the article DOI: 10.1103/PhysRevLett.116.071802.

Increased detection of carbapenemase-producing Enterobacteriaceae on post-clean sampling of a burns unit's wet surfaces

Wet surface biofilms are a potential reservoir for multidrug-resistant Gram-negative organisms, including carbapenemase-producing Enterobacteriaceae (CPE). Recognition of environmental sources is important in reducing secondary patient transmission. We report the increased detection of blaIMP-4⁺ CPE in environmental samples from floor drains in burns unit shower rooms, when collected following cleaning as compared to pre-cleaning. We propose that disruption of biofilms during cleaning may account for the increased detection of multi-resistant organisms. The results highlight the role of the wet environment as an under-recognized potential source of CPE transmission. Environmental screening focusing on pre-cleaning samples alone will likely underestimate environmental contamination.

Predictors of oncological outcomes in T1G3 patients treated with BCG who undergo radical cystectomy

PURPOSE

To evaluate the oncological impact of postponing radical cystectomy (RC) to allow further conservative therapies prior to progression in a large multicentre retrospective cohort of T1-HG/G3 patients initially treated with BCG.

METHODS

According to the time of RC, the population was divided into 3 groups: patients who did not progress to muscle-invasive disease, patients who progressed before radical cystectomy and patients who experienced progression at the time of radical cystectomy. Clinical and pathological outcomes were compared across the three groups.

RESULTS

Of 2451 patients, 509 (20.8%) underwent RC. Patients with tumors > 3 cm or with CIS had earlier cystectomies (HR = 1.79, p = 0.001 and HR = 1.53, p = 0.02, respectively). Patients with tumors > 3 cm, multiple tumors or CIS had earlier T3/T4 or N + cystectomies. In patients who progressed, the timing of cystectomy did not affect the risk of T3/T4 or N + disease at RC. Patients with T3/T4 or N + disease at RC had a shorter disease-specific survival (HR = 4.38, p < 0.001), as did patients with CIS at cystectomy (HR = 2.39, p < 0.001). Patients who progressed prior to cystectomy had a shorter disease-specific survival than patients for whom progression was only detected at cystectomy (HR = 0.58, p = 0.024) CONCLUSIONS: Patients treated with RC before experiencing progression to muscle-invasive disease harbor better oncological and survival outcomes compared to those who progressed before RC and to those upstaged at surgery. Tumor size and concomitant CIS at diagnosis are the main predictors of surgical treatment while tumor size, CIS and tumor multiplicity are associated with extravesical disease at surgery.

Measurement of Final-State Correlations in Neutrino Muon-Proton Mesonless Production on Hydrocarbon at ⟨E_{ν}⟩=3 GeV

Final-state kinematic imbalances are measured in mesonless production of ν_{μ}+A→μ^{-}+p+X in the MINERvA tracker. Initial- and final-state nuclear effects are probed using the direction of the μ^{-}-p transverse momentum imbalance and the initial-state momentum of the struck neutron. Differential cross sections are compared to predictions based on current approaches to medium modeling. These models underpredict the cross section at intermediate intranuclear momentum transfers that generally exceed the Fermi momenta. As neutrino interaction models need to correctly incorporate the effect of the nucleus in order to predict neutrino energy resolution in oscillation experiments, this result points to a region of phase space where additional cross section strength is needed in current models, and demonstrates a new technique that would be suitable for use in fine-grained liquid argon detectors where the effect of the nucleus may be even larger.

Evolution and characterisation of the AhRAF4 NB-ARC gene family induced by Aspergillus flavus inoculation and abiotic stresses in peanut

Aflatoxin contamination in peanut is a serious food safety issue to human health around the world. Finding disease resistance genes is a key strategy for genetic improvement in breeding to deal with this issue. We identified an Aspergillus flavus-induced NBS-LRR gene, AhRAF4, using a microarray-based approach. By comparison of 23 sequences from three species using phytogenetics, protein secondary structure and three-dimensional structural analyses, AhRAF4 was revealed to be derived from Arachis duranensis by recombination, and has newly evolved into a family of several members, characterised by duplications and point mutations. However, the members of the family descended from A. ipaensis were lost following tetraploidisation. AhRAF4 was slightly up-regulated by low temperature, drought, salicylic acid and ethylene, but down-regulated by methyl jasmonate. The distinct responses upon As. flavus inoculation and the differential reactions between resistant and susceptible varieties indicate that AhRAF4 might play a role in defence responses. Temporal and spatial expression and the phenotype of transformed protoplasts suggest that AhRAF4 may also be associated with pericarp development. Because tetraploid cultivated peanuts are vulnerable to many pathogens, an exploration of R-genes may provide an effective method for genetic improvement of peanut cultivars.

Antineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer

We report on multinucleon effects in low momentum transfer (<0.8  GeV/c) antineutrino interactions on plastic (CH) scintillator. These data are from the 2010-2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at a low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, Δ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate the investigation of alternate models for antineutrino scattering off nuclei.

The Role of the Thiol N-Acetylcysteine in the Prevention of Tumor Invasion and Angiogenesis

We have extensively studied the effects of N-acetylcysteine (NAC), a cytoprotective drug that can prevent in vivo carcinogenesis. Here we review our findings NAC completely inhibits gelatinolytic activity of metalloproteases and chemotactic and invasive activities of tumor cells. In addition, NAC reduces the number of lung metastases when malignant murine melanoma cells are injected into nude mice. NAC treatment decreases the weight of primary tumors and produces a dose-related increase in tumor latency. Moreover, oral administration of NAC reduces the formation of spontaneous metastases. In experimental metastasis assays, we have found a synergistic reduction in the number of lung metastases after treatment with doxorubicin (DOX) and NAC in nude mice. In tumorigenicity and spontaneous metastasis assays, the combined administration of DOX and oral NAC again has shown synergistic effects on the frequency and weight of primary tumors and local recurrences and completely prevented the formation of lung metastases. The addition of NAC to endothelial cells strongly reduces their invasive activity in response to angiogenic stimuli. NAC inhibited the degradation and release of radiolabeled type IV collagen by activated endothelial cells, indicating that NAC blocks gelatinase activity. Oral administration of NAC reduces the angiogenic response induced by KS tumor cell products, confirming the ability of NAC to inhibit the invasive activity of endothelial cells in vivo and thereby blocking angiogenesis.

Direct Measurement of Nuclear Dependence of Charged Current Quasielasticlike Neutrino Interactions Using MINERvA

Charged-current ν_{μ} interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q^{2}, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q^{2} and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions, the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different models of both initial state nucleons and final state interactions used in the neutrino oscillation experiments.