A repeating fast radio burst associated with a persistent radio source.

The dispersive sweep of fast radio bursts (FRBs) has been used to probe the ionized baryon content of the intergalactic medium1, which is assumed to dominate the total extragalactic dispersion. Although the host-galaxy contributions to the dispersion measure appear to be small for most FRBs2, in at least one case there is evidence for an extreme magneto-ionic local environment3,4 and a compact persistent radio source5. Here we report the detection and localization of the repeating FRB 20190520B, which is co-located with a compact, persistent radio source and associated with a dwarf host galaxy of high specific-star-formation rate at a redshift of 0.241 ± 0.001. The estimated host-galaxy dispersion measure of approximately [Formula: see text] parsecs per cubic centimetre, which is nearly an order of magnitude higher than the average of FRB host galaxies2,6, far exceeds the dispersion-measure contribution of the intergalactic medium. Caution is thus warranted in inferring redshifts for FRBs without accurate host-galaxy identifications.

Ab Initio Calculation of the Contact Operator Contribution in the Standard Mechanism for Neutrinoless Double Beta Decay.

Starting from chiral nuclear interactions, we evaluate the contribution of the leading-order contact transition operator to the nuclear matrix element (NME) of neutrinoless double-beta decay, assuming a light Majorana neutrino-exchange mechanism. The corresponding low-energy constant (LEC) is determined by fitting the transition amplitude of the nn→ppe^{-}e^{-} process to a recently proposed synthetic datum. We examine the dependence of the amplitude on similarity renormalization group scale and chiral expansion order of the nuclear interaction, finding that both dependences can be compensated to a large extent by readjusting the LEC. We evaluate the contribution of both the leading-order contact operator and standard long-range operator to the neutrinoless double-beta decays in the light nuclei ^{6,8}He and the candidate nucleus ^{48}Ca. Our results provide the first clear demonstration that the contact term enhances the NME in calculations with commonly used chiral two- plus three-nucleon interactions. In the case of ^{48}Ca, for example, the NME obtained with the EM(1.8/2.0) interaction is enhanced from 0.61 to 0.87(4), where the uncertainty is propagated from the synthetic datum.

The real experience of patients after liver transplantation in intensive care unit.

ABSTRACT: We aimed to explore the real experience of patients after liver transplantation in the intensive care unit (ICU).Objective sampling method was used to select patients transferred to the ICU in 10 hospitals in Zhuhai from May 2018 to August 2020. Patients need liver transplantation due to advanced liver cancer and decompensated cirrhosis. The eligibility criteria of patients mainly included liver transplant patients who were clear-minded and willing to participate in the study and had stayed in ICU. Phenomenological research methods and in-depth interviews were used in this qualitative study.The results showed that the true experience of patients after liver transplantation during ICU stay was summarized into four themes. The strengths of our qualitative research are that we can find the trend from a phenomenon through interviews and other methods to provide a directional foundation for future quantitative research. Its limitations are that it requires a lot of manpower and time, and its objectivity and universality are limited.Hospitalization experience in the ICU may lead to many negative experiences for liver transplant patients. Nurses should fully understand and pay attention to the psychological changes in patients. Nurses should take effective targeted measures to reduce or eliminate patients' fear of ICU stay and promote rehabilitation.

[Analysis of new HIV-1 infection in MSM with seroconversion determined by limiting antigen avidity enzyme immunoassay].

Objective: To evaluate the applicability of limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA, LAg for short) in determining the new HIV-1 infection status of MSM population with seroconversion and make correlation analysis of other biological indicators. Methods: The 15 cases with HIV seroconversion were found in a MSM observation cohort for calculating the HIV prevalence in Zhejiang.The subjects were conducted epidemiological investigation and sampled.The interval of infection time was estimated according to the exposure history and the time of HIV-positive confirmation.LAg, immunoblotting, CD4 cell counting and viral load test were applied in the testing of the related blood samples. McNermar test was conducted for consistency of the two methods. Results: Of 15 cases, the average age was (31.5±8.0) years old, ranging from 24 to 57 years old. The interval of infection time ranged from 40 days to 366 days, and the median was 134 days, with inter-quartile range from 89 to 180 days. A total of 7 cases were classified as new HIV-1 infection by LAg, and 8 cases were classified as chronic infection.The consistent rate was high to 86.67%, and kappa value was 0.73.The samples lacking at least two bands in p31, p51, p66 and gp120 by immunoblotting were determined as recent infection, of which the new infection proportion was significantly higher than that of other samples (P=0.029).There was no statistical difference in the distribution of CD4 counts (P=0.533) and viral loads (P=0.467) between the new infection and chronic infection groups that divided by LAg. Conclusion: By combining with exposure history, the limiting antigen avidity enzyme immunoassay can be used to estimate the new HIV-1 infection.The other biological indicators such as immunoblotting bands, CD4 cell counts and viral loads, can be used as accessory indicators in evaluating the status of new HIV-1 infection.

Ab Initio Treatment of Collective Correlations and the Neutrinoless Double Beta Decay of

Working with Hamiltonians from chiral effective field theory, we develop a novel framework for describing arbitrary deformed medium-mass nuclei by combining the in-medium similarity renormalization group with the generator coordinate method. The approach leverages the ability of the first method to capture dynamic correlations and the second to include collective correlations without violating symmetries. We use our scheme to compute the matrix element that governs the neutrinoless double beta decay of ^{48}Ca to ^{48}Ti, and find it to have the value 0.61, near or below the predictions of most phenomenological methods. The result opens the door to ab initio calculations of the matrix elements for the decay of heavier nuclei such as ^{76}Ge, ^{130}Te, and ^{136}Xe.

[Characteristics of subtypes and transmission of HIV-1 infected persons among student MSM in Zhejiang province, 2013-2015].

Objective: To investigate the characteristics of subtype diversity and transmission on HIV-1 among 12 to 30 years old student MSM in Zhejiang province. Methods: A total of 290 newly diagnosed HIV infected student MSM were selected as the research objects for molecular studies on HIV, in Zhejiang province during 2013 to 2015. Data on epidemiology and plasma samples of these people were collected. HIV-1 nucleotide sequences of pol gene regions were amplified using the RT-PCR/nested PCR method and sequenced. Phylogenetic analysis was performed to determine the HIV-1 genotypes. Characteristics of transmission mode among these cases were also analyzed. Results: A total of 290 cases, 50.3% were diagnosed in Hangzhou and 81.0% had college or above degrees. 178 sequences including 10 subtypes, were obtained, with the main subtypes as CRF01_AE (49.4%, 88/178) and CRF07_BC (39.3%, 70/178). A total of 18 molecular transmission clusters were formed (42 cases, cluster size from 2 to 4), with the proportions of clusters as 23.6% (42/178). 61.9% (26/42) of student MSM with their schools located in the same district within the transmission clusters. Their sexual partners would include both student MSM and non-student MSM. The proportion of clusters among middle school students was 38.2% (13/34), higher than that of college students (20.1%, 29/144) ( χ(2)=4.996, P<0.05). Conclusions: The HIV-1 subtypes of student MSM in Zhejiang province appeared diversity, which indicated with the diversity of sources of infection. The geographical distribution of cluster cases is relatively centralized. In order to effectively control the spread of AIDS, more attention should be paid to the sexual partners involved and to specific programs on intervention.

Ultra-fast and probe-free cellulose biosensor for visual detection of Cu2+ ions in biological samples.

Novel, portable, probe-free, liquid cellulose biosensor was explored via a facile one-pot process for Cu2+ ions detection by naked eyes. The as-prepared biosensor displayed specific recognition towards Cu2+ ions in aqueous solution, even in complex urine and serum samples within 10 s, showing fast response characteristic. There is barely any interference on the Cu2+ ions detection by other metal ions or other complex substances in urine and serum, and the corresponding detection limit is as low as 1.185, 1.9309 and 1.9154 ppm, respectively. Moreover, the cellulose biosensor could act as an excellent candidate to sense Cu2+ ions in biological samples including urine and serum from SD rats with satisfying accuracies and biocompatibility. This study exploits a potential application of cellulose in biosensing and monitoring related to Cu2+ ions.

[Magnetic resonance imaging and diffusion weighted imaging features of focal peliosis hepatis].

Objective: To investigate the MRI and diffusion weighted imaging (DWI) features of focal peliosis hepatis. Methods: The clinical data and MRI of 19 cases with focal peliosis hepatis confirmed by pathology from January 2012 to March 2018 in Zhongshan Hospital of Fudan University were retrospectively analyzed. The number, location, size, shape, signal intensity of plain scan of lesions, enhancement pattern of lesions, vessels within lesions, and perfusion disorders of hepatic parenchyma were analyzed. The apparent diffusion coefficient (ADC) values of the lesions and adjacent hepatic parenchyma were measured, then the differences between them were explored statistically. All 24 lesions were categorized into group A with tumor-related chemotherapy and group B without tumor-related chemotherapy. The differences of MR features between the two groups were explored statistically. Results: In all 24 lesions, 22 lesions were located in the right lobe, 2 lesions in the left lobe. The median size was 7.5-72.0 (24.4±17.2) mm.On T(1)WI,21 lesions showed slightly hypointensity, 1 lesion showed slightly hyperintensity and 2 lesions were isointensity; all 24 lesions showed slightly hyperintensity on T(2)WI, and isointensity or slightly hyperintensity on DWI. The mean ADC value was (1.511±0.415)×10(-3) mm(2)/s in the lesions and (1.769±0.690)×10(-3) mm(2)/s in the adjacent hepatic parenchyma, which showed no difference between the two groups (P>0.05). On dynamic MR images, 20 lesions showed gradually filling enhancement, 4 lesions showed markedly and persistent enhancement. Punctiform or filiform vessels were found in 9 lesions. Adjacent hepatic perfusion disorders showed in 8 lesions. The median lesion size was 7.5-38.5(17.6±9.8) mm in the tumor-related-chemotherapy group and 9.0-72.0(33.8±21.2) mm in the no chemotherapy group.There was significant difference between the two groups (P<0.05). Conclusions: The MRI performance of focal peliosis hepatis had a certain characteristic. MRI combined with diffusion weighted imaging could help to make diagnoses.

[Desmoplastic fibroblastoma: a clinicopathologic analysis of 7 cases].

Objective: To investigate the clinical features, immunohistochemical and differential diagnosis of desmoplastic fibroblastoma. Methods: The clinical data and pathology features of 7 cases of desmoplastic fibroblastoma were collected and immunohistochemical study were carried out in all cases with a review of the literatures. Results: There were 2 males and 5 females, with age ranging from 31 to 71 years (average and mean age were 59 and 61 years, respectively). The tumors were located in extremities and abdomen (left toe and right toe, right foot back, left leg and right thigh, right forearm and left hepatic lobe). Clinically, the tumors presented as slow growing painless masses of long standing duration. Grossly, the tumors were well-circumscribed with firm, white to gray cut-off surface. Tumor size ranged from 1.2 to 4.0 cm in maximum diameter (average 3.0 cm). Microscopically, 2 cases were located in dermis, 4 cases were located in subcutaneous and 1 case was located in liver parenchyma. It was composed of spindle-shaped or stellate cells with a fibroblastic or myofibroblastic appearance, and sparsely scattered in densely fibrous or fibromyxoid background. There was small vascular component in tumor background. At high magnification, the tumor cells were medium size with abundant cytoplasm, and the nucleus were small and always with small nucleoli. In some cases, the tumor cells were slightly larger with enlarged nuclei, but without cellular atypical and mitosis. Immunohistochemical study showed that the tumor cells were strongly positive for vimentin, desmin, S-100 protein and CD34, but CKpan was negative. α-SMA showed focal positive in one case. Ki-67 index ranged from 1% to 2%. Four cases were followed-up (ranged from 11 to 21 months, average 16.5 months) and the patients had no recurrence after surgery. Conclusions: Desmoplastic firoblastoma is a rare soft benign tumor. The differential diagnosis includes other benign or low-grade fibroblastic/myofibroblastic lesions.

[Analysis on HIV-1 subtypes and transmission clusters in newly reported HIV/AIDS cases in Yiwu, Zhejiang Province, 2016].

Objective: To understand the characteristics of distribution on HIV-1 subtypes and the transmission clusters in Yiwu in Zhejiang province. Methods: A cross-sectional study of molecular epidemiology was carried out on newly reported HIV/AIDS cases in Yiwu. RNA was extracted from 168 plasma samples, followed by RT-PCR and nest-PCR for pol gene amplification, sequencing, phylogenetic tree construction used for analyzing the subtypes and transmission clusters. Mutations on drug resistance was analyzed by CPR 6.0 online tool. Results: Subjects were mainly males (86.3%, 145/168), with average age as (39.1±13.4) years old and most of them were migrants (66.7%, 112/168). The major routes of transmission included homosexual (51.2%, 86/168) and heterosexual (48.8%, 82/168) contacts. The rate of success for sequence acquisition was 89.9% (151/168). The dominant subtypes showed as CRF01_AE (74, 49.0%) and CRF07_BC (64, 42.4%), followed by CRF08_BC (5, 3.3%), CRF55_01B (3, 2.0%), each case of subtype B, CRF45_cpx, CRF59_01B, CRF85_BC and URF (B/C). CRF45_cpx and CRF85_BC were discovered the first time in Zhejiang province. Twenty-six transmission clusters involving 65 cases were found, with the total clustered rate as 43.0% (65/151), in which the CRF01_AE clustered rate appeared as 54.1% (40/74), higher than that of CRF07_BC (21/64, 32.8%). The average size of cluster was 2.5 cases/cluster, with average size of cluster in CRF01_AE patients infected through heterosexual transmission as the largest (3.5 cases/cluster). The prevalence of transmitted drug resistance was 4.6% (7/151). Seven cases with surveillance drug resistant mutations (SDRM) were found, including 5 cases of M46L (3.3%), and one case of F77L or Y181C. Conclusion: HIV genetic diversity and a variety of transmission clusters had been noticed in this study area (Yiwu). Programs on monitoring the subtypes and transmission clusters should be continued and strengthened.

Potential of alginate fibers incorporated with drug-loaded nanocapsules as drug delivery systems.

A major problem related to the fabrication of drug-loaded fibers by wet spinning is the significant loss of load when the drugs and spinning dopes are directly mixed together. We report a novel method to fabricate drug-loaded alginate fibers by spinning an aqueous mixture containing alginate and alginate nanocapsules incorporated with drugs. The alginate fibers exhibit spotty features of nanocapsules located close to the surface of the fibers. Adsorption experiments demonstrate the superabsorbent properties of the fibers, as well as the dependence of adsorption profiles on salt ionic strength. The adsorption processes of all the fibers are well-described by the pseudo-second-order kinetics model. Drug release tests show that the cumulative release amount increased with an increase in the proportion of nanocapsules present in the fiber. In addition, the burst release behaviors of the fibers incorporated with the nanocapsules were also diminished dramatically. This work suggests that adding nanocapsules containing drugs into the spinning dopes is a promising strategy to fabricate novel drug-loaded fibers for immediate drug delivery for wound dressing.

Assessment of serum antioxidant status in patients with silicosis.

Prolonged exposure to silica dust causes an imbalance in the generation of free radicals and in the antioxidant system, thereby inducing oxidative stress. The antioxidant status of 113 silicosis patients and 116 control subjects without silicosis was examined. Serum superoxide dismutase (SOD) activity and serum levels of malondialdehyde (MDA) and glutathione (GSH) were significantly higher in silicosis patients than in controls. The GSH level in patients with stage I silicosis was higher than that in patients with other stages, but there was no difference in serum MDA level and SOD activity between disease stages. The GSH level of patients who worked with air drills was significantly lower than that of patients in other occupations, whereas the MDA level was significantly elevated in patients who used air drills. Serum SOD activity did not differ significantly according to the occupational group. It is concluded that the measurement of serum SOD, GSH and MDA levels could be beneficial in the clinical evaluation of serum antioxidant status in silicosis patients.

Enhancement of the Gibberella zeae growth inhibitory lipopeptides from a Bacillus subtilis mutant by ion beam implantation.

Bacillus subtilis JA antagonized the growth of Gibberella zeae. In order to reduce growth of this fungi pathogen to a greater extent, low-energy ion beam implantation was applied in mutant breeding. We studied the effects of different energies and different doses of nitrogen ion implantation. The mutant strain designated as JA026 was obtained showing higher inhibition activity in the screening plate. Its inhibition zone against indicator organism increased by 14.3% compared to the original strain. The electrospray ionization mass spectrometry (ESI/MS) analysis indicated that the antifungal lipopeptides produced by the mutant were identical to those produced by the wild-type strain. The mutant strain exhibited favorable properties including the high yield of antifungal lipopeptides production and faster growth over the parent strain, which suggested that this strain would be a promising biocontrol candidate in agriculture.

[Breeding of arachidonic acid producting strain by ion implantation].

With ion implantation, a high-yield arachidonic acid producting strain(Mortierella alpina) I49-N18 was selected, whose biomass was 30.80 g/L. The lipid component of biomass was 25.8%, in which AA content was 45.37%. The results showed that selected high-yield strain was steady on 250 L fermentor, whose AA yield was 4.0 g/L.

SMN oligomerization defect correlates with spinal muscular atrophy severity.

Spinal muscular atrophy (SMA) is a motor-neuron disorder resulting from anterior-horn-cell death. The autosomal recessive form has a carrier frequency of 1 in 50 and is the most common genetic cause of infant death. SMA is categorized as types I-III, ranging from severe to mild, based upon age of onset and clinical course. Two closely flanking copies of the survival motor neuron (SMN) gene are on chromosome 5q13 (ref. 1). The telomeric SMN (SMN1) copy is homozygously deleted or converted in >95% of SMA patients, while a small number of SMA disease alleles contain missense mutations within the carboxy terminus. We have identified a modular oligomerization domain within exon 6 of SMN1. All previously identified missense mutations map within or immediately adjacent to this domain. Comparison of wild-type to mutant SMN proteins of type I, II and III SMA patients showed a direct correlation between oligomerization and clinical type. Moreover, the most abundant centromeric SMN product, which encodes exons 1-6 but not 7, demonstrated reduced self-association. These findings identify decreased SMN self-association as a biochemical defect in SMA, and imply that disease severity is proportional to the intracellular concentration of oligomerization-competent SMN proteins.

Functional interaction of the bovine papillomavirus E2 transactivation domain with TFIIB.

Induction of gene expression by the papillomavirus E2 protein requires its approximately 220-amino-acid amino-terminal transactivation domain (TAD) to interact with cellular factors that lead to formation of an activated RNA polymerase complex. These interaction partners have yet to be identified and characterized. The E2 protein localizes the transcription complex to the target promoter through its carboxy-terminal sequence-specific DNA binding domain. This domain has been reported to bind the basal transcription factors TATA-binding protein and TFIIB. We present evidence establishing a direct interaction between amino acids 74 to 134 of the E2 TAD and TFIIB. Within this region, the E2 point mutant N127Y was partially defective and W99C was completely defective for TFIIB binding in vitro, and these mutants displayed reduced or no transcriptional activity, respectively, upon transfection into C33A cells. Overexpression of TFIIB specifically restored transactivation by N127Y to close to wild-type levels, while W99C remained inactive. To further demonstrate the functional interaction of TFIIB with the wild-type E2 TAD, this region was fused to a bacterial DNA binding domain (LexA:E2:1-216). Upon transfection with increasing amounts of LexA:E2:1-216, there was reduction of its transcriptional activity, a phenomenon thought to result from titration of limiting factors, or squelching. Squelching of LexA:E2:1-216, or the wild-type E2 activator, was partially relieved by overexpression of TFIIB. We conclude that a specific region of the E2 TAD functionally interacts with TFIIB.

Repair of incomplete simple syndactyly by a web flap on a subcutaneous tissue pedicle.

A new web flap on a subcutaneous tissue pedicle was developed to repair incomplete simple syndactyly. It was isolated from the top skin in syndactyly and transferred down into the depth of the web space to create a web commissure. With use of this technique, aesthetic appearance of the web and well-functioning fingers were gained. Moreover, this technique made full use of the original skin of the syndactyly, and a skin graft was not needed. We report here the operative technique, which presents another alternative for repair of incomplete simple syndactyly.