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The interaction of single quantum emitters with an optical cavity enables the realization of efficient spin-photon interfaces, an essential resource for quantum networks. The dynamical control of the spontaneous emission rate of quantum emitters in cavities has important implications in quantum technologies, e.g., for shaping the emitted photons’ waveform or for driving coherently the optical transition while preventing photon emission. Here we demonstrate the dynamical control of the Purcell enhanced emission of a small ensemble of erbium ions doped into a nanoparticle. By embedding the nanoparticles into a fully tunable high finesse fiber based optical microcavity, we demonstrate a median Purcell factor of 15 for the ensemble of ions. We also show that we can dynamically control the Purcell enhanced emission by tuning the cavity on and out of resonance, by controlling its length with sub-nanometer precision on a time scale more than two orders of magnitude faster than the natural lifetime of the erbium ions. This capability opens prospects for the realization of efficient nanoscale quantum interfaces between solid-state spins and single telecom photons with controllable waveform, for non-destructive detection of photonic qubits, and for the realization of quantum gates between rare-earth ion qubits coupled to an optical cavity. Control of quantum emitters is needed in order to enable many applications. Here, the authors demonstrate enhancement and dynamical control of the Purcell emission from erbium ions doped in a nanoparticle within a fiber-based microcavity.

An electrochemical sensor with high sensitivity for the detection of sodium nitrite was constructed based on the peroxidase-like activity of Au magnetic nanocomposites (Au@Fe3O4). The Au@Fe3O4 composite nanoparticles were green-synthesized via the reduction of gold nanoparticles (AuNPs) from waste chestnut skins combined with the sonochemical method. The nanoparticles have both the recoverability of Fe3O4 and the advantage of being able to amplify electrical signals. Furthermore, the synergistic effect of green reduction and sonochemical synthesis provides a functional approach for the preparation of Au@Fe3O4 with significant peroxidase-like activities. The physicochemical properties were characterized using transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), the Brunauer–Emmett–Teller (BET) method, and Fourier transform infrared spectroscopy (FT-IR). The electrochemical properties of sodium nitrite were determined with cyclic voltammetry (CV) and chronoamperometry (i-t). The results revealed that Au@Fe3O4 acted as a peroxidase mimic to decompose hydrogen peroxide to produce free radicals, while ·OH was the primary free radical that promoted the oxidation of sodium nitrite. With the optimal detection system, the constructed electrochemical sensor had a high sensitivity for sodium nitrite detection. In addition, the current response had a good linear relationship with the sodium nitrite concentration in the range of 0.01–100 mmol/L. The regression equation of the working curve was y = 1.0752x + 4.4728 (R2 = 0.9949), and the LOD was 0.867 μmol/L (S/N = 3). Meanwhile, the constructed detection system was outstanding in terms of recovery and anti-interference and had a good detection stability of more than 96.59%. The sensor has been successfully applied to a variety of real samples. In view of this, the proposed novel electrochemical analysis method has great prospects for application in the fields of food quality and environmental testing.

Although previous studies have reported the dysregulation of respiratory tract microbiota in infectious diseases, insufficient data exist regarding respiratory microbiota imbalances in the lower respiratory tracts (LRTs) of children with Mycoplasma pneumoniae pneumonia (MPP). Here, we analysed the microbial community using 16S rRNA gene sequencing. Finally, bronchoalveolar lavage fluid (BALF) samples from 158 children with MPP and 29 with bacterial or viral pneumonia (control group) were collected. The diversity of the microbial community was significantly different between the two groups. A significantly increased abundance of Tenericutes and Mycoplasma was detected in the MPP group, exceeding 67% and 65% of the total bacterial population, respectively. Using Mycoplasma abundance as the diagnostic method, the sensitivity and specificity of the model was 97.5% and 96.6%, respectively. Compared to the mild MPP group, lower alpha diversity and significantly increased Mycoplasma abundance were found in the severe MPP group (P < 0.01). The abundance of Mycoplasma was positively correlated with complications and clinical indices in children with severe MPP compared with children with mild MPP. Our study describes the features of the LRT microbiota of children with MPP and uncovered its association with disease severity. This finding may offer insights into the pathogenesis of MPP in children.

Abstract Background The epidemiological features of Guillain-Barré syndrome (GBS) were different in different area, comparison of the disease was needed to identify the variation and prognosis. We compare the epidemiological features of GBS in different areas in China. Method A total of 1,191 patients were included. Information was collected in patients diagnosed with GBS and its variants in middle and south China, and then retrospectively reviewed. Patients were divided into four different regions: East China(n=441), Center China(n=566), South China(n=77) and Southwest China(n=107). These subregions are mainly divided by climate and geographical location. This data was compared with data from a study in East China (Shandong, n=150) and Northeast China (Changchun, n=750). Results Patients from south and southwest China were younger than other regions (P=0.000). A summer and autumn peak were found in northern China but more patients in winter and spring days in other areas(P=0.000). Upper respiratory tract infection (URTI) was the main preceding events in all regions but rarer in center China(P=0.001). The proportion of axonal subtype was higher in center and southwest China than in other regions(P=0.001). Patients in southwest China were more serve at nadir and have the longest hospital stay (P=0.003 and P=0.000). Conclusion Seasonal variation and preceding events difference were found in different regions in China, clinical features differ among regions in China.

Background Guillain‒Barré syndrome (GBS) is an immune‐mediated peripheral neuropathy in which inflammatory cells and cytokines participate. The JAK‐STAT signaling pathway is a major pathway involved in cytokine signal transduction, but the role of this pathway in GBS is not clear. AG490 is a tyrosine kinase inhibitor that specifically inhibits JAK2 activity and downregulates STAT3 phosphorylation. The aim of this study was to investigate the function of the JAK2/STAT3 pathway in a rat model of experimental autoimmune neuritis (EAN). Methods Lewis rats were divided into three groups: the control, the EAN, and the AG490 groups. The EAN and AG490 groups were immunized with P2 peptide to create the EAN models, while the control group received an equal volume of vehicle solution without P2 peptide. Starting from Day 5 post‐immunization (PI), the AG490 group was administered AG490 (10 mg/kg) every other day, while the control and EAN groups received an equal volume of vehicle solution without AG490. All rats were weighed and evaluated according to the EAN function score (1–10) by two investigators. Rats were sacrificed on Day 16 PI, and the sciatic nerves were examined by light microscopy, indirect immunohistochemistry, and western blotting. Results AG490‐treated rats had improved clinical scores compared with those of EAN rats. Hematoxylin and eosin (H&E) and CD45 staining showed significant inflammatory infiltration of the sciatic nerve in the EAN group compared with the control group, and demonstrated reduced inflammatory infiltration in the AG490 group. Luxol fast blue (LFB) staining showed a reduction of myelin loss in the AG490 group compared with the EAN group. The levels of TGF‐β1, IFN‐γ, and IL‐6 increased in the EAN group and showed a significant decrease in rats treated with AG490. The JAK2‐STAT3 signaling pathway was activated in EAN rats, and the AG490 group showed decreased expression levels of JAK2, p‐JAK2, and p‐STAT3 compared with those of the EAN group. Immunofluorescence also showed a decrease in the levels of p‐JAK2 and p‐STAT3 in the sciatic nerve of EAN rats. Conclusions The JAK2/STAT3 signaling pathway is involved in the pathogenesis of EAN, and inhibition of this pathway can reduce the inflammatory response in EAN rats. Despite the limitations in extrapolating EAN findings to human GBS, this study provided new insights into the pathogenesis and potential therapeutic targets of human GBS. We developed the EAN model in Lewis rat, and investigated the effect of the JAK2/STAT3 pathway inhibitor AG490 on EAN. AG490 reduced the inflammatory infiltration and mitigated demyelination damage in EAN rats through the inhibition of JAK2/STAT3 signaling pathway.

Background To investigate whether hypocalcemia influenced total blood loss and transfusion rate in elderly patients with hip fracture. Methods From our hip fracture database, patients were consecutively included between January 2014 and December 2020. Serum calcium level was corrected for albumin concentration, and hypocalcaemia was defined as corrected calcium < 2.11 mmol/L. Hemoglobin and hematocrit were obtained on admission day and postoperative day, and blood transfusions were collected. According to the combination formulas of Nadler and Gross, the total blood loss of each patient was calculated. Risk factors were further analyzed by multivariate linear regression. Results A total of 583 consecutive elderly hip fracture patients were finally included (mean age 79.32 ± 8.18 years, 68.61% female). On admission, the mean serum corrected calcium level was 2.17 ± 0.14 mmol/L, and the prevalence of hypocalcemia was 33.11% (95% CI : 29.42–37.02). When comparing patients with normal calcium, hypocalcemia patients exhibited a higher blood transfusion rate (7.69% vs 16.06%, P  < 0.05), and significantly larger total blood loss (607.86 ± 497.07 ml vs 719.18 ± 569.98 ml, P  < 0.05). Multivariate linear regression analysis showed that male, anemia on admission, time from injury to hospital, intertrochanteric fracture, blood transfusion and hypocalcemia were independently associated with increased total blood loss ( P  < 0.05). Conclusion Hypocalcemia is common in elderly patients with hip fracture, and significantly associated with more total blood loss and blood transfusion. The other risk factors for increased total blood loss are male, anemia on admission, time from injury to hospital, intertrochanteric fracture, and blood transfusion. Level of evidence Level III, retrospective study.

Background Osteoarthritis (OA) is the most common form of arthritis and a leading cause of disability. This study attempted to investigate the key mRNAs and miRNAs related to OA. Patients and methods From April 17th, 2018 to May 17th, 2018, five patients with OA and three normal controls were enrolled in this present study. To identify the differentially expressed mRNAs (DEmRNAs) and miRNAs (DEmiRNAs) between patients with OA and normal controls, RNA-sequencing was performed. Then, DEmiRNA-target DEmRNAs analysis and functional annotation of DEmiRNA-target DEmRNAs were performed. To validate the RNA-sequencing results, quantitative real time-PCR (RT-PCR) and western blot analysis were performed as well. Results A total of 1068 DEmRNAs, 21 DEmiRNAs and 395 DEmiRNA-DEmRNA pairs were identified in synovial tissues of patients with OA. The functional annotation of DEmiRNA-target DEmRNAs revealed that Pathways in cancer and PI3K-Akt signaling pathway were significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. QRT-PCR and western blot results revealed that except for TLR7, the expression level of the others was consistent with the RNA-sequencing results, generally. Conclusion The findings of this present study may provide new clues for the roles of DEmRNAs and DEmiRNAs in the pathogenesis of OA.

Background Surgery is a potential trigger of Guillain-Barré syndrome (GBS), a disorder which leads to an autoimmune-mediated attack of peripheral nerves. The present study was designed to explore clinical features of post-surgical GBS compared with those of general GBS in order to provide better clinical advice to patients undergoing surgery. Methods The medical records of GBS patients who were seen at 31 tertiary hospitals in southern China between January 1, 2013 and September 30, 2016 were retrospectively analyzed. Post-surgical GBS was defined as symptoms of GBS within 6 weeks after surgery. Clinical features of post-surgical GBS are described and are compared with general GBS. Results Among the 1001 GBS patient cases examined in this study, 45 (4.5%) patient cases exhibited symptoms of GBS within 6 weeks of undergoing surgery. Within this group, 36 (80.0%) patients developed initial symptoms of limb weakness. The average interval between surgery and symptom onset was 13.31 days. The most common type of surgery which triggered GBS was orthopedic surgery, followed by neurological surgery. Compared to general GBS, post-surgical GBS was characterized by a higher proportion of severe patients (Hughes functional grading scale (HFGS) score ≥ 3) upon admission and at nadir, higher HFGS scores at discharge, and longer hospital stays. Post-surgical GBS patients also had a significantly higher frequency of the acute motor axonal neuropathy subtype (37.9 vs. 14.2, respectively; P  = 0.001). Conclusion Surgery is probably a potential trigger factor for GBS, especially orthopedic surgery. Infections secondary to surgery may play a role. The possibility of preceding (post-operative) infections was not excluded in this study. Clinical presentation of post-surgical GBS is characterized by a more severe course and poorer prognosis, and should be closely monitored. Trial registration chicTR-RRc-17,014,152 .

Background The global status of the COVID-19 pandemic is not optimistic. This is a particularly vulnerable time for patients with pre-existing headache disorders. The present study aimed to investigate the impact of the COVID-19 pandemic on headache patients in China. Methods A survey was conducted through an online survey platform on June 6, 2020. Demographic characteristics, the PHQ-9, the ISI, a COVID-19 questionnaire and a headache profile survey were included in the online questionnaire. Results Eventually, a total of 15,000 participants from China completed the online questionnaire. Among them, 2806 participants had pre-existing headache disorders. Our analysis showed reductions in the duration of headaches (3.414 ± 6.859 vs 4.033 ± 7.325 h, P <0.001), number of headache days per month (1.788 ± 2.989 vs 2.092 ± 3.694, P <0.001), and headache intensity (4.110 ± 1.609 vs 4.290 ± 1.680, P <0.001) during the COVID-19 pandemic. Smoking (OR = 1.397, 95% CI 1.090 to 1.790, P  = 0.008) and getting support from family members during social isolation (OR = 1.656, 95% CI 1.075 to 2.550, P  = 0.022) were independent factors affecting the reduction in the duration of headaches. Education level (OR = 1.478, 95% CI 1.103 to 1.980, P  = 0.009) and having a relative or acquaintance who contracted COVID-19 (OR = 0.643, 95% CI 0.458 to 0.902, P  = 0.011) were the independent factors affecting the reduction in headache severity. Living in the Wuhan area, having symptoms or a diagnosis of COVID-19 and having relatives or acquaintances who had contracted COVID-19 were associated with the worsening of headaches. Conclusions Participants experienced an overall trend towards the improvement of headaches during the COVID-19 pandemic. Family support might play an important role in the improvement of headaches.

Background The effect of Glucocorticoids (GCs) on the treatment of Guillain-Barré syndrome (GBS) has been controversial. There is no information on whether specific subtypes of GBS respond differently to GCs. In this setting, we aimed to discuss whether GCs treating yield different effects in the distinct subtypes (acute inflammatory demyelinating polyneuropathy, AIDP; acute motor axonal neuropathy, AMAN). And further, we analyzed the impact of different doses on the outcome. Methods Medical records of 448 patients with a diagnosis of classic GBS admitted to 31 tertiary hospitals, located in 14 provinces of Southern China, from 1 January 2013 to 30 September 2016, were retrospectively collected. And 251 patients treated with GCs alone (AIDP=189, AMAN=62) were reviewed and analyzed. Results After GCs treatment, the Hughes score of AIDP patients was significantly lower than that of AMAN patients at discharge ( P =0.005) and 3 months after onset ( P< 0.001). Further analysis revealed that among AIDP patients, the high-dose group had significantly shorter hospital stay ( P =0.023), lower Hughes score at nadir ( P< 0.001), at discharge ( P =0.005), and 3 months after onset ( P< 0.001), compared with the low-dose group. However, for AMAN patients, the outcome difference between groups was nonsignificant. Conclusion Our data suggest that the high doses of GCs may result, at least in part, from the side of the duration of hospital stay and short-term outcome, favorable outcomes in AIDP patients. Therefore, we cannot completely deny the priority of GCs in the treatment of GBS, because the effect of different doses of GCs varies in treating different subtypes. More studies are needed in the future to further validate this issue. Trial registration ChiCTR-RRC-17014152 . Registered 26 December 2017- Retrospectively registered.