Amorphous nickel hydroxide shell tailors local chemical environment on platinum surface for alkaline hydrogen evolution reaction.

In analogy to natural enzymes, an elaborated design of catalytic systems with a specifically tailored local chemical environment could substantially improve reaction kinetics, effectively combat catalyst poisoning effect and boost catalyst lifetime under unfavourable reaction conditions. Here we report a unique design of 'Ni(OH)2-clothed Pt-tetrapods' with an amorphous Ni(OH)2 shell as a water dissociation catalyst and a proton conductive encapsulation layer to isolate the Pt core from bulk alkaline electrolyte while ensuring efficient proton supply to the active Pt sites. This design creates a favourable local chemical environment to result in acidic-like hydrogen evolution reaction kinetics with a lowest Tafel slope of 27 mV per decade and a record-high specific activity and mass activity in alkaline electrolyte. The proton conductive Ni(OH)2 shell can also effectively reject impurity ions and retard the Oswald ripening, endowing a high tolerance to solution impurities and exceptional long-term durability that is difficult to achieve in the naked Pt catalysts. The markedly improved hydrogen evolution reaction activity and durability in an alkaline medium promise an attractive catalyst material for alkaline water electrolysers and renewable chemical fuel generation.

Role of nutrient-driven O-GlcNAc-post-translational modification in pancreatic exocrine and endocrine islet development.

Although the developing pancreas is exquisitely sensitive to nutrient supply in utero, it is not entirely clear how nutrient-driven post-translational modification of proteins impacts the pancreas during development. We hypothesized that the nutrient-sensing enzyme O-GlcNAc transferase (Ogt), which catalyzes an O-GlcNAc-modification onto key target proteins, integrates nutrient-signaling networks to regulate cell survival and development. In this study, we investigated the heretofore unknown role of Ogt in exocrine and endocrine islet development. By genetic manipulation in vivo and by using morphometric and molecular analyses, such as immunofluorescence imaging and single cell RNA sequencing, we show the first evidence that Ogt regulates pancreas development. Genetic deletion of Ogt in the pancreatic epithelium (OgtKOPanc) causes pancreatic hypoplasia, in part by increased apoptosis and reduced levels of of Pdx1 protein. Transcriptomic analysis of single cell and bulk RNA sequencing uncovered cell-type heterogeneity and predicted upstream regulator proteins that mediate cell survival, including Pdx1, Ptf1a and p53, which are putative Ogt targets. In conclusion, these findings underscore the requirement of O-GlcNAcylation during pancreas development and show that Ogt is essential for pancreatic progenitor survival, providing a novel mechanistic link between nutrients and pancreas development.

Renal denervation: recent developments in clinical and preclinical research.

PURPOSE OF REVIEW: Renal denervation represents a new dimension to hypertension treatment, with multiple device manufacturers seeking premarket FDA approval currently. Interest in the efficacy and safety of the treatment has spurred compelling mechanistic studies into the function of renal nerves and downstream impacts of denervation. RECENT FINDINGS: A trial of the ultrasound Paradise Catheter system (RADIANCE II) found a 6.3 mmHg reduction in SBP relative to sham controls. A trial of the Symplicity Spyral system (SPYRAL HTN-ON MED) found an insignificant reduction in SBP relative to sham controls. Individuals were taking antihypertensive medications during the study, and investigators note the sham group experienced a larger medication burden than the denervated group. Recent preclinical studies have evaluated potential risks of renal denervation, how sympathetic activity broadly is affected, as well as identifying possible biomarkers to identify individuals where denervation would be more successful. SUMMARY: Studies of renal denervation continue to find a robust antihypertensive effect, especially in studies wherein medications are withdrawn. Further investigation into mechanisms and indicators for usage of the technique will be important in identifying the patient population most likely to benefit from usage of renal denervation.

Sharp Signals of Boson Clouds in Black Hole Binary Inspirals.

Gravitational waves (GWs) are an exciting new probe of physics beyond the standard models of gravity and particle physics. One interesting possibility is provided by the so-called "gravitational atom," wherein a superradiant instability spontaneously forms a cloud of ultralight bosons around a rotating black hole. The presence of these boson clouds affects the dynamics of black hole binary inspirals and their associated GW signals. In this Letter, we show that the binary companion can induce transitions between bound and unbound states of the cloud, effectively "ionizing" it, analogous to the photoelectric effect in atomic physics. The orbital energy lost in this process can overwhelm the losses due to GW emission, so that ionization drives the inspiral rather than merely perturbing it. We show that the ionization power contains sharp features that lead to distinctive "kinks" in the evolution of the emitted GW frequency. These discontinuities are a unique signature of the boson cloud, and observing them would not only constitute a detection of the ultralight boson itself, but also provide direct information about its mass and the state of the cloud.

Fetal undernutrition, placental insufficiency, and pancreatic ß-cell development programming in utero.

The prevalence of obesity and type 2 (T2D) diabetes is a major health concern in the United States and around the world. T2D is a complex disease characterized by pancreatic ß-cell failure in association with obesity and insulin resistance in peripheral tissues. Although several genes associated with T2D have been identified, it is speculated that genetic variants account for only <10% of the risk for this disease. A strong body of data from both human epidemiological and animal studies shows that fetal nutrient factors in utero confer significant susceptibility to T2D. Numerous studies done in animals have shown that suboptimal maternal environment or placental insufficiency causes intrauterine growth restriction (IUGR) in the fetus, a critical factor known to predispose offspring to obesity and T2D, in part by causing permanent consequences in total functional ß-cell mass. This review will focus on the potential contribution of the placenta in fetal programming of obesity and TD and its likely impact on pancreatic ß-cell development and growth.

Targeted afferent renal denervation reduces arterial pressure but not renal inflammation in established DOCA-salt hypertension in the rat.

Recent preclinical studies show renal denervation (RDNx) may be an effective treatment for hypertension; however, the mechanism remains unknown. We have recently reported total RDNx (TRDNx) and afferent-selective RDNx (ARDNx) similarly attenuated the development of deoxycorticosterone acetate (DOCA)-salt hypertension. Whereas TRDNx abolished renal inflammation, ARDNx had a minimal effect despite an identical antihypertensive effect. Although this study established that ARDNx attenuates the development of DOCA-salt hypertension, it is unknown whether this mechanism remains operative once hypertension is established. The current study tested the hypothesis that TRDNx and ARDNx would similarly decrease mean arterial pressure (MAP) in the DOCA-salt hypertensive rat, and only TRDNx would mitigate renal inflammation. After 21 days of DOCA-salt treatment, male Sprague-Dawley rats underwent TRDNx ( n = 16), ARDNx ( n = 16), or Sham ( n = 14) treatment and were monitored for 14 days. Compared with baseline, TRDNx and ARDNx decreased MAP similarly (TRDNx -14 ± 4 and ARDNx -15 ± 6 mmHg). After analysis of diurnal rhythm, rhythm-adjusted mean and amplitude of night/day cycle were also reduced in TRDNx and ARDNx groups compared with Sham. Notably, no change in renal inflammation, injury, or function was detected with either treatment. We conclude from these findings that: 1) RDNx mitigates established DOCA-salt hypertension; 2) the MAP responses to RDNx are primarily mediated by ablation of afferent renal nerves; and 3) renal nerves do not contribute to the maintenance of renal inflammation in DOCA-salt hypertension.

New Target for Cosmic Axion Searches.

Future cosmic microwave background experiments have the potential to probe the density of relativistic species at the subpercent level. This sensitivity allows light thermal relics to be detected up to arbitrarily high decoupling temperatures. Conversely, the absence of a detection would require extra light species never to have been in equilibrium with the Standard Model. In this Letter, we exploit this feature to demonstrate the sensitivity of future cosmological observations to the couplings of axions to photons, gluons, and charged fermions. In many cases, the constraints achievable from cosmology will surpass existing bounds from laboratory experiments and astrophysical observations by orders of magnitude.

[Fatal electric accident due to adverse error situation]. / Tödlicher Stromunfall aufgrund ungünstiger Fehlerkonstellation.

Despite wearing high-impedance shoes, a young male died while trying to connect a garden pump (230 V). The cause of death could easily be determined on the basis of testimonies of eye-witnesses and an electric mark on the body. Histological and electron microscopic examinations showed metallisation of the electric mark (pure iron). Intensive investigative efforts were needed, however, to reproduce the current path, which resulted from three different coactive failures. The electrotechnical characteristics of the case and the resulting current path are described.

Repeatable Perovskite Solar Cells through Fully Automated Spin-Coating and Quenching.

Enhancing reproducibility, repeatability, as well as facilitating transferability between laboratories will accelerate the progress in many material domains, wherein perovskite-based optoelectronics are a prime use case. This study presents fully automated perovskite thin film processing using a commercial spin-coating robot in an inert atmosphere. We successfully apply this novel processing method to antisolvent quenching. This process is typically difficult to reproduce and transfer and is now enhanced to exceptional repeatability in comparison to manual processing. Champion perovskite solar cells demonstrate power conversion efficiencies as high as 19.9%, proving the transferability of established manual spin-coating processes to automatic setups. Comparison with human experts reveals that the performance is already on par, while automated processing yields improved homogeneity across the substrate surface. This work demonstrates that fully automated perovskite thin film processing improves repeatability. Such systems bear the potential to become a foundation for autonomous optimization and greatly improve transferability between laboratories.

IL-1R Mediated Activation of Renal Sensory Nerves in DOCA-Salt Hypertension.

BACKGROUND: Clinical trials of renal denervation for the treatment of hypertension have shown a variety of off-target improvements in conditions associated with sympathetic overactivity. This may be due to the ablation of sympathoexcitatory afferent renal nerves, which are overactive under conditions of renal inflammation. Renal IL (interleukin)-1ß is elevated in the deoxycorticosterone acetate-salt model of hypertension, and its activity may be responsible for the elevation in afferent renal nerve activity and arterial pressure. METHODS: Continuous blood pressure recording of deoxycorticosterone acetate-salt mice with IL-1R (IL-1 receptor) knockout or antagonism was used individually and combined with afferent renal denervation (ARDN) to assess mechanistic overlap. Protein quantification and histological analysis of kidneys were performed to characterize renal inflammation. RESULTS: ARDN attenuated deoxycorticosterone acetate-salt hypertension (-20±2-Δmm Hg mean arterial pressure [MAP] relative to control at study end) to a similar degree as total renal denervation (-21±2-Δmm Hg MAP), IL-1R knockout (-16±4-Δmm Hg MAP), or IL-1R antagonism (-20±3-Δmm Hg MAP). The combination of ARDN with knockout (-18±2-Δmm Hg MAP) or antagonism (-19±4-Δmm Hg MAP) did not attenuate hypertension any further than ARDN alone. IL-1R antagonism was found to have an acute depressor effect (-15±3-Δmm Hg MAP, day 10) in animals with intact renal nerves but not those with ARDN. CONCLUSIONS: These findings suggest that IL-1R signaling is partially responsible for the elevated afferent renal nerve activity, which stimulates central sympathetic outflow to drive deoxycorticosterone acetate-salt hypertension.

Evaluation of machine learning algorithms for noninvasive intracranial pressure estimation using near infrared spectroscopy as a covariate.

BACKGROUND: Intracranial pressure (ICP) is a vital parameter that is continuously monitored in patients with severe brain injury and imminent intracranial hypertension. OBJECTIVE: To estimate intracranial pressure without intracranial probes based on transcutaneous near infrared spectroscopy (NIRS). METHODS: We developed machine learning based approaches for noninvasive intracranial pressure (ICP) estimation using signals from transcutaneous near infrared spectroscopy (NIRS) as well as other cardiovascular and artificial ventilation parameters. RESULTS: In a patient cohort of 25 patients, with 22 used for model development and 3 for model testing, the best performing models were Fourier transform based Transformer ICP waveform estimation which produced a mean absolute error of 4.68 mm Hg (SD = 5.4) in estimation. CONCLUSION: We did not find a significant improvement in ICP estimation accuracy by including signals measured by transcutaneous NIRS. We expect that with higher quality and greater volume of data, noninvasive estimation of ICP will improve.

Targeting the aryl hydrocarbon receptor (AhR) with BAY 2416964: a selective small molecule inhibitor for cancer immunotherapy.

BACKGROUND: The metabolism of tryptophan to kynurenines (KYN) by indoleamine-2,3-dioxygenase or tryptophan-2,3-dioxygenase is a key pathway of constitutive and adaptive tumor immune resistance. The immunosuppressive effects of KYN in the tumor microenvironment are predominantly mediated by the aryl hydrocarbon receptor (AhR), a cytosolic transcription factor that broadly suppresses immune cell function. Inhibition of AhR thus offers an antitumor therapy opportunity via restoration of immune system functions. METHODS: The expression of AhR was evaluated in tissue microarrays of head and neck squamous cell carcinoma (HNSCC), non-small cell lung cancer (NSCLC) and colorectal cancer (CRC). A structure class of inhibitors that block AhR activation by exogenous and endogenous ligands was identified, and further optimized, using a cellular screening cascade. The antagonistic properties of the selected AhR inhibitor candidate BAY 2416964 were determined using transactivation assays. Nuclear translocation, target engagement and the effect of BAY 2416964 on agonist-induced AhR activation were assessed in human and mouse cancer cells. The immunostimulatory properties on gene and cytokine expression were examined in human immune cell subsets. The in vivo efficacy of BAY 2416964 was tested in the syngeneic ovalbumin-expressing B16F10 melanoma model in mice. Coculture of human H1299 NSCLC cells, primary peripheral blood mononuclear cells and fibroblasts mimicking the human stromal-tumor microenvironment was used to assess the effects of AhR inhibition on human immune cells. Furthermore, tumor spheroids cocultured with tumor antigen-specific MART-1 T cells were used to study the antigen-specific cytotoxic T cell responses. The data were analyzed statistically using linear models. RESULTS: AhR expression was observed in tumor cells and tumor-infiltrating immune cells in HNSCC, NSCLC and CRC. BAY 2416964 potently and selectively inhibited AhR activation induced by either exogenous or endogenous AhR ligands. In vitro, BAY 2416964 restored immune cell function in human and mouse cells, and furthermore enhanced antigen-specific cytotoxic T cell responses and killing of tumor spheroids. In vivo, oral application with BAY 2416964 was well tolerated, induced a proinflammatory tumor microenvironment, and demonstrated antitumor efficacy in a syngeneic cancer model in mice. CONCLUSIONS: These findings identify AhR inhibition as a novel therapeutic approach to overcome immune resistance in various types of cancers.

Genetic Ablation of the Nutrient Sensor Ogt in Endocrine Progenitors Is Dispensable for ß-Cell Development but Essential for Maintenance of ß-Cell Mass.

Previously we utilized a murine model to demonstrate that Ogt deletion in pancreatic progenitors (OgtKOPanc) causes pancreatic hypoplasia, partly mediated by a reduction in the Pdx1-expressing pancreatic progenitor pool. Here, we continue to explore the role of Ogt in pancreas development by deletion of Ogt in the endocrine progenitors (OgtKOEndo). At birth OgtKOEndo, were normoglycemic and had comparable pancreas weight and α-cell, and ß-cell mass to littermate controls. At postnatal day 23, OgtKOEndo displayed wide ranging but generally elevated blood glucose levels, with histological analyses showing aberrant islet architecture with α-cells invading the islet core. By postnatal day 60, these mice were overtly diabetic and showed significant loss of both α-cell and ß-cell mass. Together, these results highlight the indispensable role of Ogt in maintenance of ß-cell mass and glucose homeostasis.

ICU Cockpit: a platform for collecting multimodal waveform data, AI-based computational disease modeling and real-time decision support in the intensive care unit.

ICU Cockpit: a secure, fast, and scalable platform for collecting multimodal waveform data, online and historical data visualization, and online validation of algorithms in the intensive care unit. We present a network of software services that continuously stream waveforms from ICU beds to databases and a web-based user interface. Machine learning algorithms process the data streams and send outputs to the user interface. The architecture and capabilities of the platform are described. Since 2016, the platform has processed over 89 billion data points (N = 979 patients) from 200 signals (0.5-500 Hz) and laboratory analyses (once a day). We present an infrastructure-based framework for deploying and validating algorithms for critical care. The ICU Cockpit is a Big Data platform for critical care medicine, especially for multimodal waveform data. Uniquely, it allows algorithms to seamlessly integrate into the live data stream to produce clinical decision support and predictions in clinical practice.

p38 MAPK signaling in M1 macrophages results in selective elimination of M2 macrophages by MEK inhibition.

M2 macrophages promote tumor progression and therapy resistance, whereas proimmunogenic M1 macrophages can contribute to the efficacy of cytostatic and immunotherapeutic strategies. The abundance of M2 macrophages in the immune infiltrate of many cancer types has prompted the search for strategies to target and eliminate this subset. From our prior experiments in syngeneic mouse tumor models, we learned that pharmacological inhibition of mitogen-activated protein kinase kinase (MEK) did not merely result in tumor cell death, but also in the modulation of the tumor immune infiltrate. This included a prominent decrease in the numbers of macrophages as well as an increase in the M1/M2 macrophage ratio. Investigation of the mechanism underlying this finding in primary murine macrophage cultures revealed that M2 macrophages are significantly more sensitive to MEK inhibition-induced cell death than their M1 counterparts. Further analyses showed that the p38 MAPK pathway, which is activated in M1 macrophages only, renders these cells resistant to death by MEK inhibition. In conclusion, the dependency of M2 macrophages on the MEK/extracellular-signal regulated kinase (ERK) pathway empowers MEK inhibitors to selectively eliminate this subset from the tumor microenvironment.

Placental mTOR complex 1 regulates fetal programming of obesity and insulin resistance in mice.

Fetal growth restriction, or low birth weight, is a strong determinant for eventual obesity and type 2 diabetes. Clinical studies suggest placental mechanistic target of rapamycin (mTOR) signaling regulates fetal birth weight and the metabolic health trajectory of the offspring. In the current study, we used a genetic model with loss of placental mTOR function (mTOR-KOPlacenta) to test the direct role of mTOR signaling on birth weight and metabolic health in the adult offspring. mTOR-KOPlacenta animals displayed reduced placental area and total weight, as well as fetal body weight at embryonic day (E) 17.5. Birth weight and serum insulin levels were reduced; however, ß cell mass was normal in mTOR-KOPlacenta newborns. Adult mTOR-KOPlacenta offspring, under a metabolic high-fat challenge, displayed exacerbated obesity and metabolic dysfunction compared with littermate controls. Subsequently, we tested whether enhancing placental mTOR complex 1 (mTORC1) signaling, via genetic ablation of TSC2, in utero would improve glucose homeostasis in the offspring. Indeed, increased placental mTORC1 conferred protection from diet-induced obesity in the offspring. In conclusion, placental mTORC1 serves as a mechanistic link between placental function and programming of obesity and insulin resistance in the adult offspring.

Timed Ang2-Targeted Therapy Identifies the Angiopoietin-Tie Pathway as Key Regulator of Fatal Lymphogenous Metastasis.

Recent clinical and preclinical advances have highlighted the existence of a previously hypothesized lymphogenous route of metastasis. However, due to a lack of suitable preclinical modeling tools, its contribution to long-term disease outcome and relevance for therapy remain controversial. Here, we established a genetically engineered mouse model (GEMM) fragment-based tumor model uniquely sustaining a functional network of intratumoral lymphatics that facilitates seeding of fatal peripheral metastases. Multiregimen survival studies and correlative patient data identified primary tumor-derived Angiopoietin-2 (Ang2) as a potent therapeutic target to restrict lymphogenous tumor cell dissemination. Mechanistically, tumor-associated lymphatic endothelial cells (EC), in contrast to blood vascular EC, were found to be critically addicted to the Angiopoietin-Tie pathway. Genetic manipulation experiments in combination with single-cell mapping revealed agonistically acting Ang2-Tie2 signaling as key regulator of lymphatic maintenance. Correspondingly, acute presurgical Ang2 neutralization was sufficient to prolong survival by regressing established intratumoral lymphatics, hence identifying a therapeutic regimen that warrants further clinical evaluation. SIGNIFICANCE: Exploiting multiple mouse tumor models including a unique GEMM-derived allograft system in combination with preclinical therapy designs closely matching the human situation, this study provides fundamental insight into the biology of tumor-associated lymphatic EC and defines an innovative presurgical therapeutic window of migrastatic Ang2 neutralization to restrict lymphogenous metastasis.This article is highlighted in the In This Issue feature, p. 211.

Effects of compactification in D-brane inflation.

In D3-brane inflation, the inflaton potential receives important contributions from sources in the compact space, such as fluxes, other D-branes, and orientifold planes. Most previous analyses have considered only the effects of sources near to the inflationary D3-brane, but in fact distant sources do not generically decouple and can critically influence the dynamics during inflation. We provide a systematic method for incorporating the effects of arbitrary distant sources as perturbations to the local supergravity background. We use this approach to obtain the structure of the potential for a D3-brane in a warped throat geometry attached to a general compact space. A significant, and well-known, contribution to this potential arises from quantum effects involved in the stabilization of the compactification volume. Our method automatically captures these effects, encoding them in a suitable flux background.

Targeting immune-checkpoint inhibitor resistance mechanisms by MEK inhibitor and agonist anti-CD40 antibody combination therapy.

The widespread application of immune-checkpoint blockade (ICB) has resulted in unprecedented response rates in patients with immunogenic cancers, such as melanoma and lung cancer. However, sub-groups of patients with these indications do not respond to ICB, and the same applies to patients with other cancer types. Mechanisms of resistance to ICB include low tumor immunogenicity associated with low T cell infiltration ('cold' tumors), suppression of anti-tumor immunity by immunosuppressive cells in the tumor microenvironment (TME), lack of antigen-presentation and immune escape (e.g. by downregulation of MHC-I on tumor cells) as well as oncologic pathways that suppress immune responses. Combination strategies, involving cytostatic drugs, harbor the potential to overcome refractoriness to immunotherapy. However, suppression of immune cell function by cytostatic drugs may limit the efficacy. In our study, we show that combination treatment of targeted inhibition of mitogen-activated protein kinase (MAPK) kinase (MEK) and agonist immunostimulatory anti-CD40 antibody (Ab) is particularly suitable in counteracting aforementioned ICB resistance mechanisms (Fig. 1).

Radiation-induced alterations in immunogenicity of a murine pancreatic ductal adenocarcinoma cell line.

Pancreatic ductal adenocarcinoma (PDA) is highlighted by resistance to radiotherapy with the possible exception of hypofractionated irradiation. As single photon doses were reported to increase immunogenicity, we investigated dose-dependent irradiation effects on clonogenic survival, expression of immunologically relevant cell surface molecules and susceptibility to cytotoxic T cell (CTL) mediated killing using a murine PDA cell line. Clonogenicity decreased in a dose-responsive manner showing enhanced radioresistance at single photon doses below 5 Gy. Cell cycle analysis revealed a predominant G2/M arrest, being most pronounced 12 h after irradiation. Polyploidy increased in a dose- and time-dependent manner reaching a maximum frequency 60 h following irradiation with 10 Gy. Irradiation increased surface expression of MHC class I molecules and of immunological checkpoint molecules PDL-1 and CD73, especially at doses ≥ 5 Gy, but not of MHC class II molecules and CXCR4 receptors. Cytotoxicity assays revealed increased CTL lysis of PDA cells at doses ≥ 5 Gy. For the PDA cell line investigated, our data show for the first time that single photon doses ≥ 5 Gy effectively inhibit colony formation and induce a G2/M cell cycle arrest. Furthermore, expression levels of immunomodulatory cell surface molecules became altered possibly enhancing the susceptibility of tumour cells to CTL lysis.