Aligned grains and scattered light found in gaps of planet-forming disk.

Polarized (sub)millimetre emission from dust grains in circumstellar disks was initially thought to be because of grains aligned with the magnetic field1,2. However, higher-resolution multi-wavelength observations3-5 and improved models6-10 found that this polarization is dominated by self-scattering at shorter wavelengths (for example, 870 µm) and by grains aligned with something other than magnetic fields at longer wavelengths (for example, 3 mm). Nevertheless, the polarization signal is expected to depend on the underlying substructure11-13, and observations until now have been unable to resolve polarization in multiple rings and gaps. HL Tau, a protoplanetary disk located 147.3 ± 0.5 pc away14, is the brightest class I or class II disk at millimetre-submillimetre wavelengths. Here we show deep, high-resolution polarization observations of HL Tau at 870 µm, resolving polarization in both the rings and the gaps. We find that the gaps have polarization angles with a notable azimuthal component and a higher polarization fraction than the rings. Our models show that the disk polarization is due to both scattering and emission from the aligned effectively prolate grains. The intrinsic polarization of aligned dust grains is probably more than 10%, which is much higher than that expected in low-resolution observations (about 1%). Asymmetries and dust features that are not seen in non-polarimetric observations are seen in the polarization observations.

Four annular structures in a protostellar disk less than 500,000 years old.

Annular structures (rings and gaps) in disks around pre-main-sequence stars have been detected in abundance towards class II protostellar objects that are approximately 1,000,000 years old1. These structures are often interpreted as evidence of planet formation1-3, with planetary-mass bodies carving rings and gaps in the disk4. This implies that planet formation may already be underway in even younger disks in the class I phase, when the protostar is still embedded in a larger-scale dense envelope of gas and dust5. Only within the past decade have detailed properties of disks in the earliest star-forming phases been observed6,7. Here we report 1.3-millimetre dust emission observations with a resolution of five astronomical units that show four annular substructures in the disk of the young (less than 500,000 years old)8 protostar IRS 63. IRS 63 is a single class I source located in the nearby Ophiuchus molecular cloud at a distance of 144 parsecs9, and is one of the brightest class I protostars at millimetre wavelengths. IRS 63 also has a relatively large disk compared to other young disks (greater than 50 astronomical units)10. Multiple annular substructures observed towards disks at young ages can act as an early foothold for dust-grain growth, which is a prerequisite of planet formation. Whether or not planets already exist in the disk of IRS 63, it is clear that the planet-formation process begins in the initial protostellar phases, earlier than predicted by current planet-formation theories11.

A triple protostar system formed via fragmentation of a gravitationally unstable disk.

Binary and multiple star systems are a frequent outcome of the star formation process and as a result almost half of all stars with masses similar to that of the Sun have at least one companion star. Theoretical studies indicate that there are two main pathways that can operate concurrently to form binary/multiple star systems: large-scale fragmentation of turbulent gas cores and filaments or smaller-scale fragmentation of a massive protostellar disk due to gravitational instability. Observational evidence for turbulent fragmentation on scales of more than 1,000 astronomical units has recently emerged. Previous evidence for disk fragmentation was limited to inferences based on the separations of more-evolved pre-main sequence and protostellar multiple systems. The triple protostar system L1448 IRS3B is an ideal system with which to search for evidence of disk fragmentation as it is in an early phase of the star formation process, it is likely to be less than 150,000 years old and all of the protostars in the system are separated by less than 200 astronomical units. Here we report observations of dust and molecular gas emission that reveal a disk with a spiral structure surrounding the three protostars. Two protostars near the centre of the disk are separated by 61 astronomical units and a tertiary protostar is coincident with a spiral arm in the outer disk at a separation of 183 astronomical units. The inferred mass of the central pair of protostellar objects is approximately one solar mass, while the disk surrounding the three protostars has a total mass of around 0.30 solar masses. The tertiary protostar itself has a minimum mass of about 0.085 solar masses. We demonstrate that the disk around L1448 IRS3B appears susceptible to disk fragmentation at radii between 150 and 320 astronomical units, overlapping with the location of the tertiary protostar. This is consistent with models for a protostellar disk that has recently undergone gravitational instability, spawning one or two companion stars.

A study on the impact of Internet use on depression among Chinese older people under the perspective of social participation.

PURPOSE: This study aimed to evaluate the role of social participation in the relationship between internet use and depressive symptoms among Chinese older adults and investigate how the internet use interact with social participation to reduce the risk of depressive symptoms. METHODS: Based on the survey from the China Health and Retirement Longitudinal Study (CHARLS) in 2018, we identified 4645 subjects and used the Ordinary Least Square method (OLS) and Propensity Score Matching method (PSM) to identify the association between Internet use and depression of older people, and further test how social participation played a role in the relationship. RESULTS: The level of depression of older people was significantly reduced in those who using internet in China, and the effect was still robust under different identification methods. The mental health was improved when using internet because of the increase of social participation and social capital. Further, The positive effect was stronger especially in those who were female, living in rural areas, has low education attainments and were 70-79 years old. CONCLUSIONS: The popularity of internet use has a positive effect on the depressive symptoms of Chinese older adults. Effective measures were encouraged to improve the friendliness of internet for older people and promote the popularization of the Internet and older group, achieving the spiritual well-being of them in the Internet society.

Spatially resolved magnetic field structure in the disk of a T Tauri star.

Magnetic fields in accretion disks play a dominant part during the star formation process but have hitherto been observationally poorly constrained. Field strengths have been inferred on T Tauri stars and possibly in the innermost part of their accretion disks, but the strength and morphology of the field in the bulk of a disk have not been observed. Spatially unresolved measurements of polarized emission (arising from elongated dust grains aligned perpendicularly to the field) imply average fields aligned with the disks. Theoretically, the fields are expected to be largely toroidal, poloidal or a mixture of the two, which imply different mechanisms for transporting angular momentum in the disks of actively accreting young stars such as HL Tau (ref. 11). Here we report resolved measurements of the polarized 1.25-millimetre continuum emission from the disk of HL Tau. The magnetic field on a scale of 80 astronomical units is coincident with the major axis (about 210 astronomical units long) of the disk. From this we conclude that the magnetic field inside the disk at this scale cannot be dominated by a vertical component, though a purely toroidal field also does not fit the data well. The unexpected morphology suggests that the role of the magnetic field in the accretion of a T Tauri star is more complex than our current theoretical understanding.

[Modification on the interaction of glipizide with bovine serum albumin by molecular spectroscopy].

In the Tris-HCl buffer solution with pH was 7.40, the interaction between glipizide (Gli) and bovine serum albumin (BSA) was investigated by classical fluorescence spectroscopy with the change of protein as investigation object and elastic scattering fluorescence spectrometry with the change of drugs as investigation object at 293 K and 303 K, the conclusions of the two methods were consistent. Results showed that Gli could quench the intrinsic fluorescence of BSA, and the quenching mechanism was a dynamic quenching process. The hydrophobic force played an important role in the conjugation reaction between BSA and Gli, the binding site mainly located in BSA hydrophobic region and the number of binding site (n) in the binary system was approximately to 1. The values of Hill's coefficients were less than 1, which indicated the weak negative cooperativity in BSA-Gli system. The binding constant (Ka) obtained by elastic scattering fluorescence spectrometric was much larger than the one obtained by classical fluorescence spectroscopy, indiciating that it was more accurate and reasonable when using the change of drug's fluorescence as the research object. At last, the scientificalness of the new method based on elastic scattering fluorescence spectrometric was verified by ultraviolet spectroscopy. The research results showed that there existed insufficiency in analysis of the interaction of drug with protein by classical fluorescence spectroscopy with the change of protein as investigation object, and the fluorescence spectrogram only reflected partial information of the interaction between drug and protein, while the interaction between drug and protein could be better expressed by elastic scattering fluorescence spectrometry with the change of drugs as investigation object.

Readiness for Hospital Discharge After a Cesarean Section and Associated Factors Among Chinese Mothers: A Single Centre Cross-Sectional Study.

Purpose: Knowledge of the readiness for hospital discharge can help health care professionals accurately determine the patients' discharge time. However, few studies were on the readiness for discharge and its related factors among mothers with cesarean sections. Thus, this study aims to examine the readiness for hospital discharge and its associated factors among Chinese mothers with cesarean sections. Patients and Methods: A single-centre cross-sectional study was conducted from September 2020 to March 2021 in Guangzhou, China. Three hundred thirty-nine mothers with cesarean sections completed the questionnaires on demographic and obstetric characteristics, readiness for hospital discharge, quality for discharge teaching, parenting sense of competence, family function, and social support. Multiple linear regression analysis was used to identify independent factors influencing readiness for hospital discharge among mothers with cesarean sections. Results: The total score of readiness for hospital discharge was 136.47 ± 25.29. The quality of discharge teaching, parenting sense of competence, number of cesareans, family function, and attending antenatal classes were independent factors influencing the readiness for hospital discharge (P < 0.05) among mothers with cesarean sections. Conclusion: The readiness for hospital discharge of mothers with cesarean sections need to be improved. Improving the quality of discharge teaching, parenting sense of competence, and family function may help improve the readiness for hospital discharge of mothers with cesarean sections.

Fertility Histories and Heart Disease in Later Life in China.

Purpose: Based on life course theories, health among older people is driven by a continuous and cumulative process that develops over the life course. To better understand the aging process, it is important to assess associations between parity and heart disease in older people of China. Method: The associations between heart disease prevalence and number of births, number of boys or girls ever born were evaluated among 5,990 samples (mean age 64.1 years) using the Probit regression model based on the data from China Health and Retirement Longitudinal Study (CHARLS) conducted in 2013 and 2018. The model was adjusted only for rural or urban residents, and multivariate regression models were run separately by gender. Results: Our results showed that more than three children or more than two boys ever born were associated with a higher risk of heart disease. However, the number of girls ever born had no significant effect on heart disease in the elderly. We further analyzed the group difference between urban and rural residents using the regression model. More than three children or more than two boys ever born were associated with a high risk of heart disease in rural areas. Compared to urban residents, rural residents were more likely to be suffering from heart disease due to high parity. When considering the digender difference the paper found that more than three children ever born were associated with a high risk of heart disease in the female group. Late age at the time of giving birth for the first time was associated with a poorer risk level of heart disease in the rural residents, because the phenomenon of early childbearing was serious in the rural residents. But after considering the impact on the physical health of using chronic diseases, the first birth and the last birth both increased the risk of heart disease. Conclusions: Some policy implications were being put forward. Firstly, parents who were ready to give birth should be aware of the possible health loss of high parity. Postpartum nutrition supplements and chronic disease prevention were suggested to prevent heart disease in later life. Secondly, the elderly in rural areas should pay more attention to heart diseases. Participating in more daily exercise and physical examinations was a good choice to reduce the risk of heart disease. Thirdly, women who give birth prematurely have a higher risk of CVD. Based on our results, age at entry to parenthood was closely related to the risk of heart disease in later life.

Number of Births and Risk of Diabetes in China's Older Women.

As an important life event in individuals' life, childbirth will affect the health of women to different degrees. More and more attention has been paid to whether the number of births will affect the incident diabetes in elderly women, but there are few related studies. Based on the data of the Chinese Longitudinal Healthy Longevity Survey in 2018, 6,159 older women are selected as the study population. Logistic regression analyses are used to estimate the relationship between the number of births and diabetes risk. For each additional birth, the odds ratio of maternal diabetes will decrease by 6.9% and the result is significant at the 1% level, especially among mothers having four children or less. The conclusion is equally applicable in the sample of fathers and urban mothers, but the increase in the number of births will increase the risk of diabetes in rural mothers, although this result is not statistically significant. Later age at first birth, later age at last birth, the longer childbearing period, and birth interval will significantly reduce the risk of diabetes.

Volunteer Service and Well-Being of Older People in China.

Purpose: The social support theory suggested that involving older people in social activities could increase their level of social participation and interaction, which in turn improved their well-being. However, there has been a heated controversy about whether participating in volunteer services could enhance the well-being of older people, especially for the Chinese sample. Method: Based on the data from the China Health and Retirement Longitudinal Study (CHARLS) in 2013, this paper used an ordered probit model to examine the impact of older people's participation in volunteer services on their well-being, as well as the differences in the impact across groups and the specific transmission mechanism. Result: The empirical study found that Chinese older people's participation in volunteerism significantly enhanced their well-being, which remained robust after eliminating the possible effects of self-selection. Further heterogeneity analysis revealed that for female, non-party members and older adults with good economic status, participation in volunteerism has a higher increase in well-being. The mediating effect test indicated that older people's participation in volunteerism affected well-being mainly through enhancing positive emotions. Conclusion: It is necessary to promote the participation of older people in volunteer services and to clarify the role of government support and advocacy. Proper guidance is given to change the role of older people as care recipients to that of service providers and caregivers, and to continuously enrich the programmes and content of volunteer service to safeguard the well-being of older people.

Effect of Working After Retirement on the Mental Health of Older People: Evidence From China.

There is little empirical research on the effect of working after retirement on the mental health of the older adults in China. To fill this gap in the literature, this study examines the effects of working after retirement on the mental health of the older adults using data from the China Family Panel Studies. We employed the methods of ordinary least squares, ordered logit, and propensity score matching-difference in differences (PSM-DID). Results show that working after retirement is negatively related to mental health of the older adults in China. The deterioration effect of post-retirement work mainly impacts those aged over 60 years, women, and those with lower education background, urban household registration, higher pension, and higher social status. Working after retirement is negatively related to mental health through the mediating effects of deteriorating interpersonal relationships and lower positive attitude. It is necessary to consider mental health effects and their population differences to evaluate the impact and improve the quality of policies of active aging.

Internet Use and Depressive Symptoms Among Older Adults in China.

This study investigated the effect of using the Internet on depression symptoms of older Chinese, based on 7,801 adults aged over 60 years from the 2018 China Family Panel Studies. Results showed that the elderly who used the Internet reported lower depression scores, and the more frequent they use Internet, the lower their depression scores. Moreover, using the Internet for social contact and entertainment decreased the depression scores of the older adults, but when using Internet for learn, work, and commercial activity, the relief of depressive symptoms disappeared. Therelief of depression symptoms through Internet use were heterogeneous among different groups: the elderly aged 60-70, women, rural residents, and those with lower education attainment. Moreover, Internet use decreased the depression scores by increasing the frequency of contact with their children and increasing the importance of their enjoyment of life. According to the relief of depression by using Internet reasonably, policies should be designed to ensure that all ages could have easy access to the Internet.

In-Series U-Net Network to 3D Tumor Image Reconstruction for Liver Hepatocellular Carcinoma Recognition.

Cancer is one of the common diseases. Quantitative biomarkers extracted from standard-of-care computed tomography (CT) scan can create a robust clinical decision tool for the diagnosis of hepatocellular carcinoma (HCC). According to the current clinical methods, the situation usually accounts for high expenditure of time and resources. To improve the current clinical diagnosis and therapeutic procedure, this paper proposes a deep learning-based approach, called Successive Encoder-Decoder (SED), to assist in the automatic interpretation of liver lesion/tumor segmentation through CT images. The SED framework consists of two different encoder-decoder networks connected in series. The first network aims to remove unwanted voxels and organs and to extract liver locations from CT images. The second network uses the results of the first network to further segment the lesions. For practical purpose, the predicted lesions on individual CTs were extracted and reconstructed on 3D images. The experiments conducted on 4300 CT images and LiTS dataset demonstrate that the liver segmentation and the tumor prediction achieved 0.92 and 0.75 in Dice score, respectively, by as-proposed SED method.

Effects of grain alignment efficiency on synthetic dust polarization observations of molecular clouds.

It is well known that the polarized continuum emission from magnetically aligned dust grains is determined to a large extent by local magnetic field structure. However, the observed significant anticorrelation between polarization fraction and column density may be strongly affected, perhaps even dominated by variations in grain alignment efficiency with local conditions, in contrast to standard assumptions of a spatially homogeneous grain alignment efficiency. Here we introduce a generic way to incorporate heterogeneous grain alignment into synthetic polarization observations of molecular clouds (MCs), through a simple model where the grain alignment efficiency depends on the local gas density as a power law. We justify the model using results derived from radiative torque alignment theory. The effects of power-law heterogeneous alignment models on synthetic observations of simulated MCs are presented. We find that the polarization fraction-column density correlation can be brought into agreement with observationally determined values through heterogeneous alignment, though there remains degeneracy with the relative strength of cloud-scale magnetized turbulence and the mean magnetic field orientation relative to the observer. We also find that the dispersion in polarization angles-polarization fraction correlation remains robustly correlated despite the simultaneous changes to both observables in the presence of heterogeneous alignment.

First detection of equatorial dark dust lane in a protostellar disk at submillimeter wavelength.

In the earliest (so-called "Class 0") phase of Sun-like (low-mass) star formation, circumstellar disks are expected to form, feeding the protostars. However, these disks are difficult to resolve spatially because of their small sizes. Moreover, there are theoretical difficulties in producing these disks in the earliest phase because of the retarding effects of magnetic fields on the rotating, collapsing material (so-called "magnetic braking"). With the Atacama Large Millimeter/submillimeter Array (ALMA), it becomes possible to uncover these disks and study them in detail. HH 212 is a very young protostellar system. With ALMA, we not only detect but also spatially resolve its disk in dust emission at submillimeter wavelength. The disk is nearly edge-on and has a radius of ~60 astronomical unit. It shows a prominent equatorial dark lane sandwiched between two brighter features due to relatively low temperature and high optical depth near the disk midplane. For the first time, this dark lane is seen at submillimeter wavelength, producing a "hamburger"-shaped appearance that is reminiscent of the scattered-light image of an edge-on disk in optical and near infrared light. Our observations open up an exciting possibility of directly detecting and characterizing small disks around the youngest protostars through high-resolution imaging with ALMA, which provides strong constraints on theories of disk formation.

Increased expression of interleukin 17 in the cortex and hippocampus from patients with mesial temporal lobe epilepsy.

Mesial temporal lobe epilepsy (MTLE) is the most common form of focal epilepsies in adults and proinflammatory cytokines have long been thought to play an important role in pathogenesis and epileptogenicity. In the present study, we investigated the levels and expression patterns of the interleukin 17 (IL-17) system in temporal neocortex and hippocampus from 24 patients with MTLE and 8 control (Ctr) samples. We found that IL-17 and IL-17 receptor (IL-17R) were clearly upregulated in MTLE at both mRNA and protein levels, compared with Ctr. Immunostaining indicated that neurons, astrocytes, microglia and endothelial cells of blood vessels are the major sources of IL-17. These findings suggest that IL-17 system may be involved in the pathogenesis and epileptogenicity of MTLE.

Microsurgical resection of tumors lateroventral and ventral to the high cervical spinal cord.

BACKGROUND: Since there are a complex anatomic structure and vital function in the high cervical spinal cord, it is difficult to remove the tumors lateroventral and ventral to the high cervical spinal cord. This clinical study was undertaken to analyze surgical approaches, manner of tumor resection and postoperative management. METHODS: Thirty-four patients underwent microsurgical excision of tumors lateroventral and ventral to the high cervical spinal cord by means of three approaches. The tumors comprised mostly Schwannoma and meningioma (88.24%, 30/34) in this group. Tumor volume varied from 3.0 cm x 2.5 cm x 2.0 cm to 12 cm x 3.0 cm x 2.5 cm. Of the 34 patients, 4 had dumbbell-shaped tumors growing outside the spinal canal and 7 tumors growing into the intracranium. RESULTS: The tumor was totally removed in 32 patients (94.1%). Follow-up for 7 months to 6.4 years (median 3.6 years) showed a recovery of a normal life or work ability in 30 (83.3%) patients. CONCLUSION: Modified operative approaches and microsurgical techniques can raise the rate of total tumor removal and reduce the disability of patients.

DFT study on the geometric, electronic structure and Raman spectra of 5,15-diphenylporphine.

The ground state geometric, electronic structure and Raman spectra of 5,15-diphenylporphine (H(2)DPP) have been studied using B3LYP/6-31G(d) method and compared with that of well-studied free base porphine (H(2)P) and meso-tetraphenylporphine (H(2)TPP). Calculation shows that 5,15-substitution causes remarkable in-plane distortion, whereas the resulting out-of-plane distortion is negligible. The calculated electronic structure of H(2)DPP is consistent with the absorption spectra compared with H(2)P and H(2)TPP. The calculated vibrational frequencies of H(2)DPP scaled with a single factor of 0.971 agree well with experimental data (the rms error is 8.0 cm(-1)). The assignment of experimental Raman bands of H(2)DPP was discussed on the basis of theoretical calculation and the comparison with that of H(2)P and H(2)TPP. The splitting of some vibrational modes involving the motion of C(m) atom, such as nu(1), nu(8), and nu(10), was observed and was attributed to the diversification of the environment around C(m) atoms. As the shift of absorption peaks, the shift of some structure-sensitive Raman bands of H(2)DPP form that of H(2)TPP and H(2)P was attributed to the in-plane nuclear reorganization (IPNR) induced by phenyl-substitution, though the contribution of nonplanarity mechanism could not be excluded completely.

Salvianolic acid B attenuates toxin-induced neuronal damage via Nrf2-dependent glial cells-mediated protective activity in Parkinson's disease models.

Salvianolic acid B (SalB), a bioactive compound isolated from the plant-derived medicinal herb Danshen, has been shown to exert various anti-oxidative and anti-inflammatory activities in several neurological disorders. In this study, we sought to investigate the potential protective effects and associated molecular mechanisms of SalB in Parkinson's disease (PD) models. To determine the neuroprotective effects of SalB in vitro, MPP+- or lipopolysaccharide (LPS)-induced neuronal injury was achieved using primary cultures with different compositions of neurons, microglia and astrocytes. Our results showed that SalB reduced both LPS- and MPP+-induced toxicity of dopamine neurons in a dose-dependent manner. Additionally, SalB treatment inhibited the release of microglial pro-inflammatory cytokines and resulted in an increase in the expression and release of glial cell line-derived neurotrophic factor (GDNF) from astrocytes. Western blot analysis illustrated that SalB increased the expression and nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). The knockdown of Nrf2 using specific small interfering RNA (siRNA) partially reversed the SalB-induced GDNF expression and anti-inflammatory activity. Moreover, SalB treatment significantly attenuated dopaminergic (DA) neuronal loss, inhibited neuroinflammation, increased GDNF expression and improved the neurological function in MPTP-treated mice. Collectively, these findings demonstrated that SalB protects DA neurons by an Nrf-2 -mediated dual action: reducing microglia activation-mediated neuroinflammation and inducing astrocyte activation-dependent GDNF expression. Importantly the present study also highlights critical roles of glial cells as targets for developing new strategies to alter the progression of neurodegenerative disorders.