Quantum storage and manipulation of heralded single photons in atomic quantum memories

We demonstrate the storage and manipulation of narrowband heralded single photons from a cavity-enhanced spontaneous parametric downconversion (SPDC) source in the atomic quantum memory based on electromagnetically induced transparency. We show that nonclassical correlations are preserved between the heralding and the retrieved photons after storage process. By varying the intensity of the coupling field during retrieval process, we further demonstrate that the waveform or bandwidth of the single photons can be manipulated and the nonclassical correlation between the photon pairs can be even enhanced. Unlike previous works, our SPDC source is single mode in frequency, which not only reduces the experimental complexity arising from external filtering but also increases the useful photon generation rate. Our results can be scaled up with ease and thus lay the foundation for future realization of large-scale applications in quantum information processing

Shewanella soft tissue infection: case report and literature review

SummaryObjectiveTo better understand the clinical characteristics of soft tissue infections caused by Shewanella in humans.MethodsWe report a case of Shewanella soft tissue infection and review the English literature from a search of PubMed.ResultsA total of 27 adults (mean age 61.1±16.0 years) with soft tissue infections caused by Shewanella were included for analysis. Limb involvement was found in 22 (81.5%) patients, while scalp, face, perineum, lacrimal sac, and abdominal wall involvement were each found in one patient. Chronic ulcer over the leg (14 cases (51.9%)), steroid use (four cases (14.8%)), and liver cirrhosis (three cases (11.1%)) were the major underlying conditions. Shewanella bacteremia was found in 14 out of 22 patients with soft tissue infections involving the limbs. Two patients died of septicemia, giving a mortality rate of 7.4%.ConclusionsShewanella soft tissue infections usually develop in immunocompromised patients with a preexisting cutaneous ulcer (particularly over the legs) after marine environment or seawater exposure. In view of the possible catastrophic consequences, education on the prevention of Shewanella soft tissue infections in at-risk people (e.g., the immunocompromised or elderly with a cutaneous ulcer) relating the need to avoid exposure to the marine environment or seawater may be of importance

Seabed gas emissions and submarine landslides off SW Taiwan

Methane emissions out of the seabed could seriously affect Earthâs climate and are usually associated with the dissociation of gas hydrates stored in marine sediments on the continental margins. Spatially, gas emissions out of the seafloor are not evenly distributed in continental margins. Gas emissions out of the seabed generally occur through submarine mud volcanoes and gas seeps. To understand the seabed gas emissions off SW Taiwan, we investigate the distributions of active submarine mud volcanoes, gas seeps, and gas plumes off SW Taiwan. We examine all of the available sub-bottom profiler and EK echo sounder data. We identified 19 submarine mud volcanoes, 220 gas seeps, and 295 gas plumes. The gas emissions are generally distributed at the crests of mud diapiric ridges. Most of the active mud volcanoes and gas seeps cluster at the KASMVG (Kaoping submarine mud volcanoes group) area. We speculate that the intensive mud volcanism and gas seepage at the KASMVG area are ascribed to submarine channel erosion along the continental slope base. The erosion causes a deep V-shaped channel and a steep BSR (Bottom-Simulating Reflector) slope curve across the continental margin. The upward migration rate of free gas beneath the BSR is thus increased and intensifies mud volcanism and gas seepage at the KASMVG area. The gas seeps can reduce the slope stability and generate small-scale slides. The development of mud volcanoes in an area could effectively disturb the seabed morphology so that large-scale submarine landslides cannot easily happen

Serotonin receptor HTR6-mediated mTORC1 signaling regulates dietary restriction-induced memory enhancement

Dietary restriction (DR; sometimes called calorie restriction) has profound beneficial effects on physiological, psychological, and behavioral outcomes in animals and in humans. We have explored the molecular mechanism of DR-induced memory enhancement and demonstrate that dietary tryptophan-a precursor amino acid for serotonin biosynthesis in the brain-and serotonin receptor 5-hydroxytryptamine receptor 6 (HTR6) are crucial in mediating this process. We show that HTR6 inactivation diminishes DR-induced neurological alterations, including reduced dendritic complexity, increased spine density, and enhanced long-term potentiation (LTP) in hippocampal neurons. Moreover, we find that HTR6-mediated mechanistic target of rapamycin complex 1 (mTORC1) signaling is involved in DR-induced memory improvement. Our results suggest that the HTR6-mediated mTORC1 pathway may function as a nutrient sensor in hippocampal neurons to couple memory performance to dietary intake

Sequence Variants of ADIPOQ

Diabetes is a serious global health problem. Large-scale genome-wide association studies identified loci for type 2 diabetes mellitus (T2DM), including adiponectin (ADIPOQ) gene and transcription factor 7-like 2 (TCF7L2), but few studies clarified the effect of genetic polymorphisms of ADIPOQ and TCF7L2 on risk of T2DM. We attempted to elucidate association between T2DM and polymorphic variations of both in Taiwan’s Chinese Han population, with our retrospective case-control study genotyping single nucleotide polymorphisms (SNPs) in ADIPOQ and TCF7L2 genes both in 149 T2DM patients and in 139 healthy controls from Taiwan. Statistical analysis gauged association of these polymorphisms with risk of T2DM to show ADIPOQ rs1501299 polymorphism variations strongly correlated with T2DM risk (P=0.042), with rs2241766 polymorphism being not associated with T2DM (P=0.967). However, both polymorphisms rs7903146 and rs12255372 of TCF7L2 were rarely detected in Taiwanese people. This study avers that ADIPOQ rs1501299 polymorphism contributes to risk of T2DM in the Taiwanese population

Non-prompt surgery for patients with acute type A aortic dissection without pre-operative shock and malperfusion

BackgroundAcute type A aortic dissection (ATAAD) requires urgent surgical treatment. However, during daily practice, there were some patients with ATAAD sought for medical attention several days after symptoms occurred and some other patients hesitated to receive aortic surgery after the diagnosis of ATAAD was made. This study aims to investigate the surgical outcomes of non-prompt aortic surgery (delayed diagnosis caused by the patient or delayed surgery despite immediate diagnosis) for ATAAD patients.MethodsFrom November 2004 to June 2020, of more than 200 patients with ATAAD patients who underwent aortic surgery at our hospital, there were 30 patients without pre-operative shock and malperfusion who sought for medical attention with symptoms for several days or delayed aortic surgery several days later despite ATAAD was diagnosed. Of the 30 patients (median age 60.9, range 33.4~82.5 years) in the study group, there were 18 patients undergoing surgery when they arrived at our hospital (delayed diagnosis by the patient) and 12 patients receiving surgery days later (delayed surgery despite immediate diagnosis). Patients with prompt surgery after symptom onset (control group) were matched from our database by propensity score matching. The surgical mortality rate and post-operative morbidities were compared between the study group and control group.ResultsThe in-hospital mortality was 3.3% for the study group and 6.7% for the control group (p = non-significant). The incidence of post-operative cerebral permanent neurological defect was 0% for the study group and 13.3% for the control group (p = 0.112). There were three patients receiving aortic re-intervention or re-do aortic surgery during follow-up for the study group and two patients for the control group.ConclusionPrompt surgery for ATAAD is usually a good choice if everything is well prepared. Besides, urgent but non-prompt aortic surgery could also provide acceptable surgical results for ATAAD patients without pre-operative shock and malperfusion who did not seek medical attention or who could not make their minds to undergo surgery immediately after symptom onset. Hospitalization with intensive care is very important for pre-operative preparation and monitoring for the patients who decline prompt aortic surgery

ENU Mutagenesis Identifies Mice with Morbid Obesity and Severe Hyperinsulinemia Caused by a Novel Mutation in Leptin

BACKGROUND: Obesity is a multifactorial disease that arises from complex interactions between genetic predisposition and environmental factors. Leptin is central to the regulation of energy metabolism and control of body weight in mammals. METHODOLOGY/PRINCIPAL FINDINGS: To better recapitulate the complexity of human obesity syndrome, we applied N-ethyl-N-nitrosourea (ENU) mutagenesis in combination with a set of metabolic assays in screening mice for obesity. Mapping revealed linkage to the chromosome 6 within a region containing mouse Leptin gene. Sequencing on the candidate genes identified a novel T-to-A mutation in the third exon of Leptin gene, which translates to a V145E amino acid exchange in the leptin propeptide. Homozygous Leptin(145E/145E) mutant mice exhibited morbid obesity, accompanied by adipose hypertrophy, energy imbalance, and liver steatosis. This was further associated with severe insulin resistance, hyperinsulinemia, dyslipidemia, and hyperleptinemia, characteristics of human obesity syndrome. Hypothalamic leptin actions in inhibition of orexigenic peptides NPY and AgRP and induction of SOCS1 and SOCS3 were attenuated in Leptin(145E/145E) mice. Administration of exogenous wild-type leptin attenuated hyperphagia and body weight increase in Leptin(145E/145E) mice. However, mutant V145E leptin coimmunoprecipitated with leptin receptor, suggesting that the V145E mutation does not affect the binding of leptin to its receptor. Molecular modeling predicted that the mutated residue would form hydrogen bond with the adjacent residues, potentially affecting the structure and formation of an active complex with leptin receptor within that region. CONCLUSIONS/SIGNIFICANCE: Thus, our evolutionary, structural, and in vivo metabolic information suggests the residue 145 as of special function significance. The mouse model harboring leptin V145E mutation will provide new information on the current understanding of leptin biology and novel mouse model for the study of human obesity syndrome