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Multichannel meta-imaging, inspired by the parallel-processing capability of neuromorphic computing, offers considerable advancements in resolution enhancement and edge discrimination in imaging systems, extending even into the mid- to far-infrared spectrum. Currently typical multichannel infrared imaging systems consist of separating optical gratings or merging multi-cameras, which require complex circuit design and heavy power consumption, hindering the implementation of advanced human-eye-like imagers. Here, we present printable graphene plasmonic photodetector arrays driven by a ferroelectric superdomain for multichannel meta-infrared imaging with enhanced edge discrimination. The fabricated photodetectors exhibited multiple spectral responses with zero-bias operation by directly rescaling the ferroelectric superdomain instead of reconstructing the separated gratings. We also demonstrated enhanced and faster shape classification (98.1%) and edge detection (98.2%) using our multichannel infrared images compared with single-channel detectors. Our proof-of-concept photodetector arrays simplify multichannel infrared imaging systems and offer potential solutions in efficient edge detection in human-brain-type machine vision. Here, the authors report the realization of a multichannel mid-infrared imaging system based on zero-bias type-printed graphene plasmonic photodetector arrays on ferroelectric substrates, showing enhanced infrared image recognition and edge detection accuracy. [ABSTRACT FROM AUTHOR]

Ubiquitination, catalyzed usually by a three-enzyme cascade (E1, E2, E3), regulates various eukaryotic cellular processes. E3 ligases are the most critical components of this catalytic cascade, determining both substrate specificity and polyubiquitination linkage specificity. Here, we reveal the mechanism of a naturally occurring E3-independent ubiquitination reaction of a unique human E2 enzyme UBE2E1 by solving the structure of UBE2E1 in complex with substrate SETDB1-derived peptide. Guided by this peptide sequence-dependent ubiquitination mechanism, we developed an E3-free enzymatic strategy SUE1 (sequence-dependent ubiquitination using UBE2E1) to efficiently generate ubiquitinated proteins with customized ubiquitinated sites, ubiquitin chain linkages and lengths. Notably, this strategy can also be used to generate site-specific branched ubiquitin chains or even NEDD8-modified proteins. Our work not only deepens the understanding of how an E3-free substrate ubiquitination reaction occurs in human cells, but also provides a practical approach for obtaining ubiquitinated proteins to dissect the biochemical functions of ubiquitination. Ubiquitin E3 ligases are key to accessing ubiquitinated proteins, but only a few substrates have defined E3 ligases. Here, the authors reveal the mechanism of naturally occurring E3-independent ubiquitination and develop an E3-free enzymatic strategy for the versatile generation of ubiquitinated proteins. [ABSTRACT FROM AUTHOR]

In radiotherapy, air-filled ion chamber detectors are ubiquitously used in routine dose measurements for treatment planning. However, its use has been restricted by intrinsic low spatial resolution barriers. We developed one procedure for patient-specific quality assurance (QA) in arc radiotherapy by coalescing two adjacent measurement images into a single image to improve spatial resolution and sampling frequency, and investigated how different spatial resolutions affect the QA results. PTW 729 and 1500 ion chamber detectors were used for dosimetric verification via coalescing two measurements with 5 mm-couch shift and the isocenter, and only isocenter measurement, which we call coalescence and standard acquisition (SA). Statistical process control (SPC), process capability analysis (PCA), and receiver operating characteristic (ROC) curve were used to compare the performance of the two procedures in determining tolerance levels and identifying clinically relevant errors. By analyzing 1256 γ values calculated on interpolated data points, our results indicated that detector 1500 showed higher averages in coalescence cohorts at different tolerance criteria and the dispersion degrees were spread out smaller. Detector 729 yielded a slightly lower process capability of 0.79, 0.76, 1.10, and 1.34, but detector 1500 exhibited somewhat different results of 0.94, 1.42, 1.19, and 1.60 in magnitude. The results of SPC individual control chart showed that cases in coalescence cohorts with γ values lowering its lower control limit (LCL) were greater than those in SA cohorts for detector 1500. A combination of the width of multi-leaf collimator (MLC) leaf, the cross-sectional area of the single detector, and the spacing between adjacent detectors might lead to discrepancies in percent γ values across diverse spatial resolution scenarios. The accuracy of reconstructed volume dose is mainly determined by the interpolation algorithm used in dosimetric systems. The magnitude of filling factor in the ion chamber detectors determined its ability to detect dose deviations. SPC and PCA results indicated that coalescence procedure could detect more potential failure QA results than SA while enhancing action thresholds. [ABSTRACT FROM AUTHOR]

The reduction pathway of nitrate (NO3−) and nitrite (NO2−) to nitric oxide (NO) contributes to regulating many physiological processes. To examine the rate and extent of dietary nitrate absorption and its reduction to nitrite, we supplemented rat diets with Na15NO3-containing water (1 g/L) and collected plasma, urine and several tissue samples. We found that plasma and urine showed 8.8- and 11.7-fold increases respectively in total nitrate concentrations in 1-day supplementation group compared to control. In tissue samples—gluteus, liver and eyes—we found 1.7-, 2.4- and 4.2-fold increases respectively in 1-day supplementation group. These increases remained similar in 3-day supplementation group. LC–MS/MS analysis showed that the augmented nitrate concentrations were primarily from the exogenously provided 15N-nitrate. Overall nitrite concentrations and percent of 15N-nitrite were also greatly increased in all samples after nitrate supplementation; eye homogenates showed larger increases compared to gluteus and liver. Moreover, genes related to nitrate transport and reduction (Sialin, CLC and XOR) were upregulated after nitrate supplementation for 3 days in muscle (Sialin 2.3-, CLC1 1.3-, CLC3 2.1-, XOR 2.4-fold) and eye (XOR 1.7-fold) homogenates. These results demonstrate that dietary nitrate is quickly absorbed into circulation and tissues, and it can be reduced to nitrite in tissues (and likely to NO) suggesting that nitrate-enriched diets can be an efficient intervention to enhance nitrite and NO bioavailability. [ABSTRACT FROM AUTHOR]

The antifungal agent 5-fluorocytosine (5-FC) is used for the treatment of several mycoses, but is unsuitable for monotherapy due to the rapid development of resistance. Here, we show that cryptococci develop resistance to 5-FC at a high frequency when exposed to concentrations several fold above the minimal inhibitory concentration. The genomes of resistant clones contain alterations in genes relevant as well as irrelevant for 5-FC resistance, suggesting that 5-FC may be mutagenic at moderate concentrations. Mutations in FCY2 (encoding a known permease for 5-FC uptake), FCY1, FUR1, UXS1 (encoding an enzyme that converts UDP-glucuronic acid to UDP-xylose) and URA6 contribute to 5-FC resistance. The uxs1 mutants accumulate UDP-glucuronic acid, which appears to down-regulate expression of permease FCY2 and reduce cellular uptake of the drug. Additional mutations in genes known to be required for UDP-glucuronic acid synthesis (UGD1) or a transcriptional factor NRG1 suppress UDP-glucuronic acid accumulation and 5-FC resistance in the uxs1 mutants. Pathogenic fungi rapidly develop resistance to the antifungal agent 5-fluorocytosine (5-FC). Here, Chang et al. explore the mechanisms by which Cryptococcus develops 5-FC resistance at a high frequency, including mutations in several genes and altered levels of key metabolites. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: Metformin is the only approved oral agent for youth with type 2 diabetes but its mechanism of action remains controversial. Recent data in adults suggest a primary role for the enteroinsular pathway, but there are no data in youth, in whom metformin efficacy is only ~50%. Our objectives were to compare incretin concentrations and rates of glucose production and gluconeogenesis in youth with type 2 diabetes before and after short-term metformin therapy compared with peers with normal glucose tolerance (NGT). Methods: This is a case–control observational study in youth with type 2 diabetes who were not on metformin (n = 18) compared with youth with NGT (n = 10) who were evaluated with a 2 day protocol. A 75 g OGTT was administered to measure intact glucagon-like 1 peptide (iGLP-1), gastric inhibitory polypeptide (GIP) and peptide YY (PYY). Insulinogenic index (IGI) and whole-body insulin sensitivity were calculated using glucose and insulin levels from the OGTT. Basal rates of gluconeogenesis (2H2O), glucose production ([6,6-2H2]glucose) and whole-body lipolysis ([2H5]glycerol) were measured after an overnight fast on study day 2. Youth with type 2 diabetes (n = 9) were subsequently evaluated with an identical 2 day protocol after 3 months on the metformin study. Results: Compared with individuals with NGT, those with type 2 diabetes had higher fasting (7.8 ± 2.5 vs 5.1 ± 0.3 mmol/l, mean ± SD p = 0.002) and 2 h glucose concentrations (13.8 ± 4.5 vs 5.9 ± 0.9 mmol/l, p = 0.001), higher rates of absolute gluconeogenesis (10.0 ± 1.7 vs 7.2 ± 1.1 μmol [kg fat-free mass (FFM)]−1 min−1, p < 0.001) and whole-body lipolysis (5.2 ± 0.9 vs 4.0 ± 1.4 μmol kgFFM−1 min−1, p < 0.01), but lower fasting iGLP-1 concentrations (0.5 ± 0.5 vs 1.3 ± 0.7 pmol/l, p < 0.01). Metformin decreased 2 h glucose (pre metformin 11.4 ± 2.8 vs post metformin 9.9 ± 1.9 mmol/l, p = 0.04) and was associated with ~20–50% increase in IGI (median [25th–75th percentile] pre 1.39 [0.89–1.47] vs post 1.43 [0.88–2.70], p = 0.04), fasting iGLP-1 (pre 0.3 ± 0.2 vs post 1.0 ± 0.7 pmol/l, p = 0.02), 2 h iGLP (pre 0.4 ± 0.2 vs post 1.2 ± 0.9 pmol/l, p = 0.06), fasting PYY (pre 6.3 ± 2.2 vs post 10.5 ± 4.3 pmol/l, p < 0.01) and 2 h PYY (pre 6.6 ± 2.9 vs post 9.0 ± 4.0 pmol/l, p < 0.01). There was no change in BMI, insulin sensitivity or GIP concentrations pre vs post metformin. There were no differences pre vs post metformin in rates of glucose production (15.0 ± 3.9 vs 14.9 ± 2.2 μmol kgFFM−1 min−1, p = 0.84), absolute gluconeogenesis (9.9 ± 1.8 vs 9.7 ± 1.7 μmol kgFFM−1 min−1, p = 0.76) or whole-body lipolysis (5.0 ± 0.7 vs 5.3 ± 1.3 μmol kgFFM−1 min−1, p = 0.20). Post metformin iGLP-1 and PYY concentrations in youth with type 2 diabetes were comparable to levels in youth with NGT. Conclusions/interpretation: Overall, the improved postprandial blood glucose levels and increase in incretins observed in the absence of changes in insulin sensitivity and gluconeogenesis, support an enteroinsular mechanistic pathway in youth with type 2 diabetes treated with short-term metformin. [ABSTRACT FROM AUTHOR]

Background: Controversy persists about whether additional induction chemotherapy (ICT) before neoadjuvant chemoradiation (NCRT) yields improved oncological outcomes. We performed a systematic review and meta-analysis to compare ICT+ NCRT+ surgery(S) with NCRT+ S in patients with locally advanced rectal cancer (LARC). Methods: We searched the PubMed, EMBASE, Cochrane Library, and China Biology Medicine (CBM) databases. The data were analyzed with Stata version 12.0 software. Results: We identified 9 relevant trials that enrolled 1538 patients. We detected no significant difference in the 5-year overall survival (OS) (OR 1.50, 95% CI 0.48–4.64), disease-free survival (DFS) (OR 1.03, 95% CI 0.73–1.46), local recurrence (LR) (OR 0.80, 95% CI 0.45–1.43), and distant metastasis (DM) rates (OR 1.03, 95% CI 0.55–1.93) between patients who did and did not receive ICT. The addition of ICT before NCRT had a similar pathological complete response rate compared to NCRT (OR 1.26, 95% CI 0.90–1.77). Our findings suggest that between the ICT + NCRT+S and NCRT+S groups, ICT improved the incidence of grade 3 to 4 toxicity effects (OR 4.81, 95% CI 2.38–9.37), but between the ICT + NCRT+S and NCRT+S+ adjuvant chemotherapy (ACT) groups, ICT might reduce toxicity (OR 0.19, 95% CI 0.08–0.50). ICT had no significant impact on surgical complications (OR 0.97, 95% CI 0.63–1.51). Conclusions: The addition of ICT before NCRT seemingly shows no survival benefit on patients with LARC, and might increase the toxicity. [ABSTRACT FROM AUTHOR]

Leucine-responsive regulatory proteins (Lrps) are a family of transcription factors involved in diverse biological processes in bacteria. So far, molecular mechanism of Lrps for regulating antibiotics biosynthesis in actinomycetes remains largely unexplored. This study, for the first time in Streptomyces lincolnensis, identified an Lrp (named as SLCG_Lrp) associated with lincomycin production. SLCG_Lrp was validated to be a positive regulator for lincomycin biosynthesis by directly stimulating transcription of two structural genes (lmbA and lmbV), three resistance genes (lmrA, lmrB and lmrC), and a regulatory gene (lmbU) within the lincomycin biosynthetic gene (lin) cluster. SLCG_Lrp was transcriptionally self-inhibited and triggered the expression of its adjacent gene SLCG_3127 encoding a LysE superfamily protein. Further, the binding site of SLCG_Lrp in the intergenic region of SLCG_3127 and SLCG_Lrp was precisely identified. Inactivation of SLCG_3127 in S. lincolnensis resulted in yield improvement of lincomycin, which was caused by intracellular accumulation of proline and cysteine. Arginine and phenylalanine were identified as specific regulatory ligands, respectively, to reduce and promote DNA-binding affinity of SLCG_Lrp. We further found that SLCG_Lrp was directly repressed by SLCG_2919, the first identified transcription factor outside lin cluster for lincomycin production. Therefore, our findings revealed SLCG_Lrp-mediated transcriptional regulation of lincomycin biosynthesis. This study extends the understanding of molecular mechanisms underlying lincomycin biosynthetic regulation. [ABSTRACT FROM AUTHOR]

Vertebral metastases are a common manifestation in patients with advanced cancer and treatment is often ineffective. This study was conducted to explore the efficacy of treating vertebral metastases by percutaneous vertebroplasty (PVP) combined with interventional chemotherapy. Seventy-five patients with vertebral metastases (42 men, 33 women; ages 31–76 years) were divided into 2 groups: 39 cases were treated by PVP combined with chemotherapy (VPCC group), and 36 cases were treated by PVP alone (VP group). All procedures were guided by computed tomography (CT) scanning. The results and complications were evaluated by a questionnaire regarding pain and routine follow-up. The response rate was significantly higher in the VPCC group than in the VP group (93.0% vs 74.4%, P<0.05); total response rates for the VPCC and VP groups were 25.6% and 10.3% respectively. A common complication related to VPCC was transient aggravating pain. PVP may ameliorate pain, and consolidate the vertebrae of patients with vertebral metastases. Its short-term effect may be enhanced by adding drugs into the bone cement. [ABSTRACT FROM AUTHOR]