[Molecular characteristics and drug susceptibility analysis of Streptococcus agalactiae from respiratory specimen sources].

To study the carriage status of drug susceptibility, clonal complex groups, serotypes, surface proteins and virulence genes of Streptococcus agalactiae from respiratory specimen sources. A total of 35 strains of S.agalactiae meeting the criteria were collected from 3 hospitals in 2 locations, Tangshan and Jinan. The age span of the patients was 3 days-92 years, and the percentage of elderly patients≥60 years was 71.5%.The susceptibility to 9 antimicrobial drugs was measured and analyzed using the micro broth dilution method. The strains were 100.0% sensitive to penicillin, linezolid, vancomycin, and ceftriaxone; However, it exhibits high resistance rates to erythromycin, clindamycin and levofloxacin, at 97.1%, 85.7% and 82.9% respectively; and the resistance rates to tetracycline and chloramphenicol were 34.3% and 14.2%, respectively. Genome sequence determination and analysis showed that 16 resistance genes were detected in 35 strains, among which: macrolide and lincosamide resistance genes were mainly ermB, with a carrying rate of 74.2%; tetracycline resistance genes were mainly tetM, with a carrying rate of 25.7%; in addition, the mutation rates of the quinolone resistance determinants gyrA and parC were 88.5% and 85.7%, respectively. 35 strains belonged to 6 ST types and 4 clonal groups, with CC10/ST10 as the main one, accounting for 62.8%; they contained 4 serotypes of Ⅰb, Ⅱ, Ⅲ, and Ⅴ, as well as 1 untyped strain, with serotype Ⅰb as the main one, accounting for 65.7%. The strains carried three pilus types, PI1+PI2a, PI2a and PI2b types, respectively, and detected five surface proteins, alpha, alp1, rib, srr, and rdf_0594, and seven virulence factors, cba, cfb, cylE, fbsA, hylB, lmb, and pavA. Overall, S.agalactiae isolated from respiratory tract specimens is predominantly sourced from elderly patients, with CC10 strains being most prevalent. These strains harbor multiple drug-resistant and virulence genes, demonstrating elevated resistance rates to macrolides, lincosamides, and quinolones. This emphasizes the necessity for vigilant attention to the health threat posed by S. agalactiae from respiratory tract speciments of elderly patients.

[Research progress on physical activity of childhood cancer survivors].

Many childhood cancer survivors are suffering serious and long-lasting complications or sequelae, taking a significant toll on their health. Adequate physical activity can be effective in mitigating the negative effects of these complications or sequelae. However, low levels of physical activity are prevalent among childhood cancer survivors. Due to the lack of guidelines on physical activity for childhood cancer survivors, there are many difficulties in correctly guiding childhood cancer survivors to participate in physical activity. Therefore, it is necessary to summarize the relevant studies on the physical activity of childhood cancer survivors. This article provides a review of the concept and measurement of physical activity, recommended amount, and the participation of childhood cancer survivors both domestically and internationally, in order to provide a reference for promoting the physical activity level of Chinese childhood cancer survivors.

Serum tryptophan metabolites are associated with erosive hand osteoarthritis and pain: results from the DIGICOD cohort.

OBJECTIVE: To investigate host and gut-microbiota related Tryptophan metabolism in hand osteoarthritis (HOA). METHODS: The baseline serum concentration of 20 Tryptophan metabolites was measured in 416 HOA patients in a cross-sectional analysis of the DIGICOD cohort. Tryptophan metabolites levels, metabolite-ratios and metabolism pathway activation were compared between erosive (N = 141) and non-erosive HOA (N = 275) by multiple logistic regressions adjusted on age, BMI and sex. The association between Tryptophan metabolite levels and HOA symptoms was investigated by a Spearman's rank correlation analysis. RESULTS: Four serum Tryptophan metabolites, eight metabolite ratios and one metabolism pathway were associated with erosive HOA. Erosive HOA was negatively associated with Tryptophan (odds ratio (OR) = 0.41, 95% confidence interval [0.24-0.70]), indole-3-aldehyde (OR = 0.67 [0.51-0.90]) and 3-OH-anthranilic acid (OR = 1.32 [1.13-1.54]) and positively with 5-OH-Tryptophan levels (OR = 1.41 [1.13-1.77]). The pro-inflammatory kynurenine-indoleamine 2,3-dioxygenase pathway was upregulated in erosive HOA (OR = 1.60 [1.11-2.29]). Eleven metabolites were correlated with HOA symptoms and were mostly pain-related. Serotonin and N-acetyl serotonin levels were negatively correlated with number of tender joints. Indole-3-aldehyde level was negatively correlated and 3-OH-anthranilic acid, 3-OH-kynurenine and 5-OH-Tryptophan levels were positively correlated with number of patients-reported painful joints. Quinolinic acid and 3-OH-kynurenine levels correlated positively with AUSCAN pain. CONCLUSIONS: Tryptophan metabolites disturbance is associated with erosive HOA and pain and emphasize the role of low-grade inflammation and gut dysbiosis in HOA.

Coherent Picture on the Pure Spin Transport between Ag/Bi and Ferromagnets.

In a joint effort of both experiments and first-principles calculations, we resolve a hotly debated controversy and provide a coherent picture on the pure spin transport between Ag/Bi and ferromagnets. We demonstrate a strong inverse Rashba-Edelstein effect (IREE) at the interface in between Ag/Bi with a ferromagnetic metal (FM) but not with a ferromagnetic insulator. This is in sharp contrast to the previously claimed IREE at Ag/Bi interface or inverse spin Hall effect dominated spin transport. A more than one order of magnitude modulation of IREE signal is realized for different Ag/Bi-FM interfaces, casting strong tunability and a new direction for searching efficient spintronics materials.

Phase front retrieval and correction of Bessel beams.

Bessel beams generated with non-ideal axicons are affected by aberrations. We introduce a method to retrieve the complex amplitude of a Bessel beam from intensity measurements alone, and then use this information to correct the wavefront and intensity profile using a deformable mirror.

Optical Guiding in Meter-Scale Plasma Waveguides.

We demonstrate a new highly tunable technique for generating meter-scale low density plasma waveguides. Such guides can enable laser-driven electron acceleration to tens of GeV in a single stage. Plasma waveguides are imprinted in hydrogen gas by optical field ionization induced by two time-separated Bessel beam pulses: The first pulse, a J_{0} beam, generates the core of the waveguide, while the delayed second pulse, here a J_{8} or J_{16} beam, generates the waveguide cladding, enabling wide control of the guide's density, depth, and mode confinement. We demonstrate guiding of intense laser pulses over hundreds of Rayleigh lengths with on-axis plasma densities as low as N_{e0}∼5×10^{16} cm^{-3}.

[Advances in the treatment of anterior commissure combined with early glottic carcinoma].

Summary Early glottic laryngeal cancer usually refers to the Tis-T2 lesion without cervical lymph node and distant metastases. Radiotherapy of early glottic laryngeal cancer, CO2 laser microsurgery, open surgery, plasma radiofrequency ablation, photodynamic therapy, biological targeting therapy have achieved good therapeutic effect. However, due to the special nature of its anatomy, it is controversial about the treatment of early glottic laryngeal cancer which involves the anterior commissure. In this article, we reviewed the conventional treatment of radiation therapy, CO2 laser microsurgery, open surgery, plasma radiofrequency ablation.

MeV electron acceleration at 1 kHz with <10 mJ laser pulses: erratum.

In this erratum the funding section of Opt. Lett.42, 215 (2017)OPLEDP0146-959210.1364/OL.42.000215 has been updated.

Laser wakefield acceleration with mid-IR laser pulses.

We report on, to the best of our knowledge, the first results of laser plasma wakefield acceleration driven by ultrashort mid-infrared (IR) laser pulses (λ=3.9 µm, 100 fs, 0.25 TW), which enable near- and above-critical density interactions with moderate-density gas jets. Relativistic electron acceleration up to ∼12 MeV occurs when the jet width exceeds the threshold scale length for relativistic self-focusing. We present scaling trends in the accelerated beam profiles, charge, and spectra, which are supported by particle-in-cell simulations and time-resolved images of the interaction. For similarly scaled conditions, we observe significant increases in the accelerated charge, compared to previous experiments with near-infrared (λ=800 nm) pulses.

MeV electron acceleration at 1 kHz with <10 mJ laser pulses.

We demonstrate laser-driven acceleration of electrons to MeV-scale energies at 1 kHz repetition rate using <10 mJ pulses focused on near-critical density He and H2 gas jets. Using the H2 gas jet, electron acceleration to ∼0.5 MeV in ∼10 fC bunches was observed with laser pulse energy as low as 1.3 mJ. Increasing the pulse energy to 10 mJ, we measure ∼1 pC charge bunches with >1 MeV energy for both He and H2 gas jets.

[Experiences of rescuing infective arterial hemorrhage and pseudoaneurysm in DCD kidney transplantation].

Objective: To summarize experiences of rescuing arterial hemorrhage and pseudoaneurysm caused by infection in donation after cardiac death (DCD) kidney transplantation. Methods: A total of 198 consecutive DCD kidney transplantations between 1 June 2013 and 30 July 2016 in the Third Affiliated Hospital of Sun Yat-sen University were retrospectively analyzed. The means of rescuing infective arterial hemorrhage and pseudoaneurysm after operation and their therapeutic effects were summarized. Results: A total of 5 infective arterial hemorrhage, 2 infective pseudoaneurysm with hemorrhage, and 1 infective pseudoaneurysm developed in 198 DCD kidney transplantation recipients with total morbidity of 4.0%, and the morbidity of fungal infection accounted for 2.5%. One case received open surgical therapy. Two cases were treated with endovascular interventional therapy. Five cases received combined treatments of open surgery and endovascular intervention. Selective antibiotics were used based on drug sensitivity test postoperation. The wound was drained, and the drainage was repeatedly cultured to monitor the pathogen till the results turned to negative. Five patients received graft nephrectomy and were restored to hemodialysis. Two patients were successfully rescued with stable graft function. One case died. The mortality of patient was 1/8. Graft loss rate was 5/8. Both patients with stable graft function were mainly treated by intervention. Conclusions: Infective arterial hemorrhage and pseudoaneurysm were primary risk factors causing patient/graft death postoperation in DCD kidney transplantation. Endovascular therapy can be used as an effective rescuing method under the circumstance of infection. The measure allows opportunity of successfully rescuing kidney graft and deserves recommendation.

[Massive hemorrhage caused by fungal infections after donation-after-cardiac-death kidney transplantation: clinical features, prevention and treatment experience].

OBJECTIVE: To study the characteristics and prevention and treatment strategies of massive hemorrhage caused by fungal infections after donation-after-cardiac-death (DCD) kidney transplantation. METHODS: A total of 91 cases of DCD kidney transplantation between August 25, 2013 and June 30, 2015 in Third Affiliated Hospital of Sun Yat-sen Univservity were retrospectively analyzed. The characteristics of and prevention and treatments strategies for postoperative massive hemorrhage caused by fungal infections were summarized. RESULTS: Ninety-one cases of DCD kidney transplantation were divided into 2 groups based on regimens for preventing postoperative fungal infections: fluconazole prophylaxis group: a total of 26 cases of renal transplant before June 11, 2014 received fluconazole regimen, from postoperative day 0 to 2 weeks; micafungin prophylaxis group: a total of 65 cases of renal transplant after June 11, 2014 received micafungin regimen, also for 2 weeks from postoperative day 0. Two cases in fluconazole group developed postoperative massive hemorrhage. In case 1, the hemorrhage occurred at 2 weeks after transplantation. Graft nephrectomy was performed during surgical exploration for hemostasis, yet the massive hemorrhage relapsed 2 weeks later. Endoluminal exclusion of external iliac artery using endovascular covered stent-graft at the anastomosis site was performed and the massive bleeding was successfully stopped. The patient was restored to hemodialysis and waited for second kidney transplantation. Candia albicans was detected in the culture of blood and drainage liquid from incision. The other case of hemorrhage occurred at 3 weeks after transplantation. Graft nephrectomy plus endovascular exclusion using covered stent-graft were also performed to stop the massive bleeding. Massive fungal hyphae and spores were observed at the stump of renal graft artery under microscope. The patient received second kidney transplantation after 6 months successfully. No massive hemorrhage caused by fungal infections occurred in micafungin prophylaxis group. CONCLUSIONS: Massive hemorrhage cased by fungal infections after DCD kidney transplantation is usually characterized by delayed and recurrent course, and may result in graft nephrectomy or even death of patients. Endovascular exclusion using covered stent can successfully stop bleeding and rescue life of patients. Two-week preemptive prophylaxis of fungal infections using micafungin can effectively prevent delayed fungal massive hemorrhage in DCD kidney transplantation.

Unveiling the Mechanism for the Split Hysteresis Loop in Epitaxial Co2Fe1-xMnxAl Full-Heusler Alloy Films.

Utilizing epitaxial Co2Fe1-xMnxAl full-Heusler alloy films on GaAs (001), we address the controversy over the analysis for the split hysteresis loop which is commonly found in systems consisting of both uniaxial and fourfold anisotropies. Quantitative comparisons are carried out on the values of the twofold and fourfold anisotropy fields obtained with ferromagnetic resonance and vibrating sample magnetometer measurements. The most suitable model for describing the split hysteresis loop is identified. In combination with the component resolved magnetization measurements, these results provide compelling evidences that the switching is caused by the domain wall nucleation and movements with the switching fields centered at the point where the energy landscape shows equal minima for magnetization orienting near the easy axis and the field supported hard axis.

Multi-MeV Electron Acceleration by Subterawatt Laser Pulses.

We demonstrate laser-plasma acceleration of high charge electron beams to the ∼10 MeV scale using ultrashort laser pulses with as little energy as 10 mJ. This result is made possible by an extremely dense and thin hydrogen gas jet. Total charge up to ∼0.5 nC is measured for energies >1 MeV. Acceleration is correlated to the presence of a relativistically self-focused laser filament accompanied by an intense coherent broadband light flash, associated with wave breaking, which can radiate more than ∼3% of the laser energy in a ∼1 fs bandwidth consistent with half-cycle optical emission. Our results enable truly portable applications of laser-driven acceleration, such as low dose radiography, ultrafast probing of matter, and isotope production.

Spectroscopic study of Gd nanostructures quantum confined in Fe corrals.

Low dimensional nanostructures have attracted attention due to their rich physical properties and potential applications. The essential factor for their functionality is their electronic properties, which can be modified by quantum confinement. Here the electronic states of Gd atom trapped in open Fe corrals on Ag(111) were studied via scanning tunneling spectroscopy. A single spectroscopic peak above the Fermi level is observed after Gd adatoms are trapped inside Fe corrals, while two peaks appear in empty corrals. The single peak position is close to the higher energy peak of the empty corrals. These findings, attributed to quantum confinement of the corrals and Gd structures trapped inside, are supported by tight-binding calculations. This demonstrates and provides insights into atom trapping in open corrals of various diameters, giving an alternative approach to modify the properties of nano-objects.

Combining Diffusion Tensor Imaging and Susceptibility Weighted Imaging on the Substantia Nigra of 1-Methyl-4-Phenyl-1, 2, 3, 6-Tetrahydropyridine (MPTP)-induced Rhesus Monkey Model of Parkinson's Disease.

Objective: The aim of this study was to evaluate whether combining diffusion tensor magnetic resonance imaging (DTI) and susceptibility weighted imaging (SWI) techniques would provide a sensitive method for differentiating between 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced rhesus monkey model of Parkinson's disease (PD) and wild-type controls. Subjects and Methods: Seventeen rhesus monkeys were divided into two groups. A series of intramuscular injections of either saline (control group, n = 8) or MPTP (0.2 mg/kg body weight; PD group, n = 9) were given to the monkeys, twice a week. Then, SWI and DTI scans were obtained from the monkeys with Siemens Magnetom Verio 3.0T superconductive MRI system. Region of interest analysis was performed on substantia nigra pars compacta (SNc) and substantia nigra pars reticulata (SNr). In addition, immunohistochemical staining of tyrosine hydroxylase was applied to assess degeneration of SN dopaminergic neurons. Results: Monkeys in the PD group displayed mild to moderate motor symptoms assessed using Kurlan's scale. With SWI scans, decreased width of SNc but increased width of SNr was found in PD group monkeys compared to controls. Calculation of the ratios of widths of SNc and SNr to the anterior and posterior mesencephalic diameter also reflected narrower SNc but wider SNr than controls. Decreased SWI signal intensity of SNc and SNr suggested iron deposition in both subregions of SN. The DTI scans showed lower fractional anisotropy (FA) values in SNc of the PD group monkeys, while no change of FA values in SNr was detected. Immunohistochemical test displayed generalized loss of dopaminergic neurons in SN of PD group monkeys. Conclusion: Combining the use of DTI and SWI can provide a sensitive method for differentiating between MPTP-induced rhesus monkey model of PD and wild-type controls. This effective imaging modality might provide additional information for characteristic identification of PD at early stages, thus enhancing the ability to make early diagnosis, and monitor progression of the natural history and treatment effects.

Physical origins of the new magnetoresistance in Pt/YIG.

A new type of magnetoresistance (MR) observed in Pt/YIG when nominally nonmagnetic Pt comes in contact with a ferrimagnetic insulator yttrium iron garnet (YIG) has drawn intense experimental and theoretical interest. In this Letter, we experimentally demonstrate two physical origins of the new MR: a spin current across the Pt/YIG interface and the magnetic proximity effect. The new MR can also be reproduced when Pt is in contact with a nonmagnetic insulator doped with a few percent of Fe impurities. By tuning the YIG surface and inserting an Au layer between the Pt and YIG, we are able to separate the two contributions.

Inverse spin Hall effect in a ferromagnetic metal.

The inverse spin Hall effect (ISHE) has been observed only in nonmagnetic metals, such as Pt and Au, with a strong spin-orbit coupling. We report the observation of ISHE in a ferromagnetic permalloy (Py) on ferromagnetic insulator yttrium iron garnet (YIG). Through controlling the spin current injection by altering the Py-YIG interface, we have isolated the spin current contribution and demonstrated the ISHE in a ferromagnetic metal, the reciprocal phenomenon of the anomalous Hall effect. A large spin Hall angle in Py, determined from Py thin films of different thicknesses, indicates many other ferromagnetic metals may be exploited as superior pure spin current detectors and for applications in spin current.

Creating an artificial two-dimensional Skyrmion crystal by nanopatterning.

A Skyrmion crystal typically arises from helical spin structures induced by the Dzyaloshinskii-Moriya interaction. Experimentally its physical exploration has been impeded because it is a rarity and is found only within a narrow temperature and magnetic field range. We present a method for the assembly of a two-dimensional Skyrmion crystal based upon a combination of a perpendicularly magnetized film and nanopatterned arrays of magnetic vortices that are geometrically confined within nanodisks. The practical feasibility of the method is validated by micromagnetic simulations and computed Skyrmion number per unit cell. We also quantify a wide range in temperature and field strength over which the Skyrmion crystal can be stabilized without the need for any intrinsic Dzyaloshinskii-Moriya interactions, which otherwise is needed to underpin the arrangement as is the case in the very few known Skyrmion crystal cases. Thus, our suggested scheme involves a qualitative breakthrough that comes with a substantial quantitative advance.

A model of isolated, vascular whole thymus transplantation in nude rats.

BACKGROUND: We used a model of vascularized thymus lobes as a whole isolated organ transplantation in rats. MATERIALS AND METHODS: Male Fisher rats (F344, RT11v1; n = 10) and male homozygous Rowett nude rats (rnu/rnu; n = 10) were used as donors and recipients, respectively. Both vascular lobes of the thymus as a whole isolated organ were heterotopically transplanted to the neck of recipients. The right common carotid artery of the donor thymus was anastomosed end-to-end to the homonymous artery of the recipient. The anterior vena cava and the left brachiocephalic vein of the donor thymus were anastomosed end-to-side to the right and left external jugular veins of the recipient, respectively. Histological examination was used to monitor graft viability; graft function was assessed using flow cytometry (FCM) and immunologic effects by skin grafts in vivo. RESULTS: All recipients survived. Preparation of the donors and recipients took 35.6 ± 5.5 minutes and 60.3 ± 15.1 minutes, respectively. The blood supply to the thymus graft was patent. Histology of the thymus on postoperative days 14, 56, and 112 revealed viable grafts with preserved microarchitecture. FCM analysis showed 37.18 ± 11.1% CD3+ T cells at day 21 after transplantation. Skin grafts from F344 and Rowett rats survived 8-10 and more than 30 days, respectively, whereas all third-party Sprague Dawley grafts were rejected within 5 days. CONCLUSION: We developed a novel model of isolated, direct vascularized whole thymus transplantation in nude rats, in which both lobes of the fully vascularized thymus were harvested en bloc for successful transplantation.