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Background The co-occurrence of insomnia and hypersomnia symptoms in patients with major depressive disorder (MDD) is associated with suicidal ideation and functional impairment. The relationship between sleep disturbances and clinical features and outcomes may not be adequately studied. In this study, we measured the functional impairments and clinical features of co-occurring insomnia and hypersomnia symptoms in Chinese patients with MDD. Methods A post-hoc analysis was performed on data from the National Survey on Symptomatology of Depression (NSSD), which assessed the MDD patients in 32 hospitals by a clinician-rating questionnaire. The clinical features and outcomes were compared among the following four groups: insomnia symptom only, hypersomnia symptom only, both insomnia and hypersomnia symptoms, no sleep disturbance, respectively. Results Totally, 234 (7.15%) of 3275 participants with MDD co-occurred insomnia and hypersomnia symptoms. They had more depressive symptoms (27.41 ± 9.123), higher rate of suicide ideation (39.7%), more severe impairment in physical (58.1%), economic (32.9%), work (55.1%), and relationship with families (29.5%). Patients with both sleep disturbances were more likely to excessive worry about sleep, have suicidal ideation, the distress of social disharmony, more somatic symptoms, lack of energy, hyperphagia, loss of mood reactivity, and diurnal change, whereas less likely to have anxious mood. Limitations Sleep disorders were not diagnosed by current standard diagnostic criteria. Conclusions Patients co-occurring with both sleep disturbances are associated with a higher rate of suicide risk and poorer social function. Our study could provide implications for suicidal risk evaluation and the development of therapeutic strategies for depression.

The North China Plain (NCP) in East Asia has a severe air pollution problem. In this study, the long-term spatial distribution and interannual trends of aerosol optical depth (AOD) were investigated using the MODIS MAIAC (multiangle implementation of the atmospheric correction) dataset from 2001 to 2020 for Tianjin, a city on the NCP. The annual AOD in Tianjin was 0.59 from 2001 to 2020. The average AOD of Tianjin was the highest in summer (0.96), followed by spring (0.58) and autumn (0.51). The annual AOD in Tianjin increased significantly in 2008 (approximately 0.77), and the minimum annual AOD was observed in 2020 (0.41). In summer, AOD in the 11 districts of Tianjin significantly increased from 2001 to 2010 and gradually decreased from 2011 to 2020. The occurrence frequency of AOD in the range of 0.2–0.5 was high in Tianjin accounting for almost 40% of the total proportion. In Tianjin, AOD exhibited a positive trend from 2001 to 2008 and an obvious negative growth trend from 2009 to 2020 due to anthropogenic emission. The findings are valuable for analyzing the climatological characteristics of aerosol loading and their optical properties at the district level of cities on the NCP.

Air pollution has become a serious problem driven by the mesoscale-circulation system in the Beijing–Tianjin–Hebei area over the North China Plain. In this study, the particulate matter (PM) levels and gaseous pollutant concentrations during 2018 were examined in Tianjin. The vertical structure of meteorological data at the 250-m tower and the characteristics of turbulence evolution were used to analyse the pollutant occurrence and development during the severe pollutant cases. The maximum PM2.5 values observed in March (~77.1 μg m−3) and November (82.4 μg m−3) as well as the higher PM10 concentration in March–April (~100.0 μg m−3) highlight the contribution of both fine mode and coarse mode particles over Tianjin. The prevailing southerly wind in April was mainly sea winds with larger wind speed at surface and high-altitudes (1.35 m s−1 to 7.98 m s−1), and changed to land breeze in September south-westerly with lower relative humidity (37.6%–46.5%) at 250 m. The photochemical reaction of O3 was affected by the moderate-to-high air temperature, and the distribution of NO2 and SO2 was attributable to the emission and gas-particle transformation under different humidity conditions. The hourly PM2.5 concentration sharply increased to 2.6–5.8 times and lasted for 28–38 h (exceeded 200 μg m−3) during the two pollution events. The variation of turbulent characteristics at different heights could be depressed due to the development of heavy pollution and otherwise could be enhanced by solar radiation. These findings could facilitate understanding the fine structure of temperature-humidity systems and the turbulence characteristics in the boundary layers during typical pollutant events, and their regional climate effects over coastal northern plain cities.

In this paper, quartz crystal microbalance (QCM) humidity sensors based on polypyrrole (PPy) modified tin disulfide (SnS2) nanocomposite have been fabricated. The morphology and composition of the PPy/SnS2 nanocomposite film were examined by means of SEM and TEM. The hydrophilicity of the PPy/SnS2 nanocomposite film sensor was verified by the contact angle experiment. The humidity sensing characteristics of the PPy/SnS2 nanocomposite sensor was studied at room temperature. The experimental results illustrated that the PPy/SnS2 nanocomposite coated QCM sensor was very sensitive to humidity and demonstrated high sensitivity, short response time, and excellent repeatability, which was surpassed the pure PPy and pure SnS2. The Langmuir adsorption model is used to explain the humidity sensing mechanism of PPy/SnS2 based QCM sensor. The enhanced humidity sensing properties are attributed to the nanostructure and hydrophilicity of the PPy/SnS2 nanocomposite.

A room temperature sub-ppb hydrogen sulfide (H2S) gas sensors based on tin oxide/reduced graphene oxide/polyaniline (SnO2/rGO/PANI) was synthesized by in-situ polymerization technique. The SnO2/rGO/PANI nanocomposite film was fabricated on a flexible polyethylene terephthalate (PET) substrate with interdigital electrodes (IDEs). The SnO2/rGO/PANI sensor possesses excellent sensing characteristics such as high response, fast response/recovery time, stable repeatability, outstanding selectivity and long-term stability. The response of SnO2/rGO/PANI film sensor prepared by in-situ polymerization is 23.9 toward 200 ppb H2S, which is two times higher than that of physical doping method, and the limit of detection is 50 ppb. The experimental result reveals that the SnO2/rGO/PANI sensor is an excellent candidate to detect H2S gas in exhaled human breath for early diagnosis of halitosis. The underlying sensing mechanism of the SnO2/rGO/PANI sensing device towards H2S gas is due to the high surface area of SnO2/rGO/PANI film, chemisorption of oxygen on surface of SnO2 hollow spheres and the special role of heterojunction.

Metal-organic frameworks-derived zinc oxide nanopolyhedra/S, N: graphene quantum dots/polyaniline (ZnO/S, N: GQDs/PANI) ternary nanohybrid was synthesized by in-situ polymerization route. The ZnO/S, N: GQDs/PANI nanocomposite was fabricated on a flexible polyethylene terephthalate (PET) substrate with interdigital electrodes. The acetone-sensing properties of the ZnO/S, N: GQDs/PANI nanocomposite sensor were investigated by exposing it to various concentrations of acetone at room temperature. The ZnO/S, N: GQDs/PANI sensor demonstrated high response, fast response/recovery time, stable repeatability, excellent selectivity, outstanding long-term stability, and ppb-level sensitivity for trace acetone detection at room temperature. These results render the ZnO/S, N: GQDs/PANI film sensor a promising candidate for acetone sensing at room temperature. The underlying sensing mechanism of the ZnO/S, N: GQDs/PANI sensor toward acetone gas ascribed to the synergistic effect and heterojunction created in the ZnO/S, N: GQDs/PANI nanocomposite.

Flexible humidity sensors with ultrafast response are great importance in the promising wearable devices. In this paper, a novel nanocomposite of tin disulfide/graphene oxide nanoflower (SnS2/GO) was first synthesized for constructing humidity sensors. The nanostructural, morphological and compositional properties of the SnS2/GO hybrid were characterized by XRD, XPS, FT-IR, SEM, TEM and EDS. The humidity experiment found that SnS2/GO (in the wt% ratio of 1:2.5) has the most excellent response. The humidity sensing results revealed the SnS2/GO film sensor has ultrahigh response, negligible hysteresis, favorable reversibility and ultrafast response/recovery behavior, which outstrips the individual SnS2 or GO film sensor. The potential mechanism of water molecule adsorption was revealed, and the complex impedance spectroscopy and Bode diagrams were used to further explain the sensing mechanisms of the SnS2/GO composite. Moreover, the impedance changes caused by the bending effect, human respiration and fingertip approaching/retracting behavior were investigated, which demonstrate a great potential of the SnS2/GO sensor in humidity sensing for wearable applications.

In this paper, a high-performance liquefied petroleum gas (LPG) sensor based on zinc oxide/polypyrrole/lead sulfide quantum dots (ZnO/PPy/PbS QDs) nanocomposite film was demonstrated, which was fabricated by layer-by-layer self-assembly and successive ionic layer adsorption and reaction technique. The nanostructure features of the as-prepared ZnO/PPy/PbS nanocomposite film were confirmed by various characterization techniques. The room temperature gas-sensing investigation of the ZnO/PPy/PbS QDs nanocomposite sensor was performed against LPG gas in a wide concentration range. The experimental results showed an outstanding response for LPG sensing at room temperature compared with previous reports, the response can reach 45.47% at 1000 ppm LPG. And it also demonstrated good selectivity and excellent repeatability. The sensing mechanism of the PPy/ZnO/PbS QDs nanocomposite film gas sensor is owing to the p-n heterojunction created at the ZnO/PPy interface, as well as much more active adsorption sites.

A high-performance acetone gas sensor based on metal-organic frameworks (MOFs)-derived ZnO/Co3O4 nano-heterostructure was prepared by a facile precipitation reaction method. The as-synthesized ZnO/Co3O4 nanocomposite was characterized by X-ray diffraction (XRD), thermo-gravimetric (TG), scanning electron microscopy (SEM), energy dispersive X-ray spectra (EDS), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), confirming its successful preparation and reasonability. The acetone sensing properties of ZnO/Co3O4 hollow polyhedron sample was investigated at the optimum working temperature of 300 °C. The experimental results reveal that the ZnO/Co3O4 nanocomposite has a significantly enhancement in acetone sensing performance, which showed high response, good linearity, short response/recovery time, excellent repeatability and outstanding selectivity. These results render the ZnO/Co3O4 hollow polyhedron an efficient sensing material for constructing high-performance acetone sensor. The mechanism of the enhanced acetone sensing performance were attributed to unique hollow nanostructure, catalytic effect of Co3O4 and the p-n heterojunctions in the ZnO/Co3O4 nanocomposite.

We report the production of flexible integrated MoS2 ion sensor arrays (FIMA) which demonstrated excellent mechanical flexibility (strain limits of 1%) and stability (bending 1000 cycles). We systematically investigated the influence of strain on the sensing performance and underling mechanism of MoS2 sensors, which is critical to flexible devices. Strain variation from -0.17% to 0.17% resulted in 29% enhancement of ion sensitivity due to energy band change, indicating tunable sensing performance of MoS2 by strain applied. The low-cost simple-structured FIMA realized simultaneous and multiplexed detection of Na+, Cd2+, Hg2+, and Pb2+ at trace concentration with excellent selectivity. Rapid (8 s) label-free detection of Cd2+ was achieved with detection limit of 5 ng/mL. Flexible MoS2 sensor arrays also exhibited the capability of monitoring Hg2+ in tap water and Na+ in human sweat samples, respectively. The FIMA show promise to an essential sensing platform for flexible/wearable devices.

The extraordinary properties of black phosphorus (BP) make it an attracting candidate for next-generation chemical sensors. BP is strain-sensitive due to piezoresistive effect, but the impact of strain on BP chemical sensing performance is still unknown which is critical to flexible devices. Additionally, BP sensor integration is highly desired because of the complexity of real samples, but it remains only theoretically explored. Here, we developed flexible integrated BP sensor arrays (FIBA) functionalized with ionophore, which demonstrated excellent mechanical flexibility (strain limits of 1%) and stability (bending 500 times). Small strain variation (from 0.33% to −0.16%) resulted in 175% enhancement of sensitivity due to Schottky barrier modulation. Rapid (4 s) label-free detection of 1 μg/L Hg2+ was achieved, within the permissible limit of the guideline for drinking water quality provided by the World Health Organization (WHO). The low-cost simple-structured FIBA realized multiplexed detection of Hg2+, Cd2+, Pb2+, and Na+ at trace concentration with excellent selectivity. FIBA also exhibited the ability of monitoring target ions in real samples (Cd2+ in tap water and Na+ in human sweat). These results demonstrate that FIBA is a promising candidate for wide range of vital signs or environment monitoring.

This paper demonstrates an ultra-highly sensitive ammonia gas sensor based on polypyrrole/zinc stannate (PPy/Zn2SnO4) nanocomposite. The PPy/Zn2SnO4 nanocomposite was synthesized by layer-by-layer alternative deposition of PPy nanospheres and Zn2SnO4 hollow spheres. The as-prepared sample was characterized by X-ray diffraction (XRD), FT-IR spectrums, scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS) and transmission electron microscope (TEM). The gas-sensing properties of the PPy/Zn2SnO4 nanofilm were investigated upon exposure to ammonia gas. The result showed that the PPy/Zn2SnO4 nanofilm sensor exhibited lower detection limit, higher response, faster response/recovery time, outstanding repeatability toward NH3 gas, which was greatly superior to the pure PPy and Zn2SnO4 counterparts. Such dramatically enhancement of gas-sensing properties for PPy/Zn2SnO4 nanofilm is attributed to the deprotonation/protonation process of ammonia adsorption/desorption on PPy surface, special interactions at p-n heterojunction, and high surface area of PPy/Zn2SnO4 nanocomposite.

Molybdenum disulfide (MoS2) is a promising nanomaterial for chemical sensing due to its exceptional properties. However, it is extremely sensitive to illumination and converts the energy of photons absorbed into photocurrent, which has hampered efforts to explore the sensing performance and underlying transduction mechanism of intrinsic MoS2. Here we systematically explored the sensing behavior of intrinsic MoS2 and the impact of illumination. In dark environment, MoS2 demonstrated record-high sensitivity reaching 1030 for pH change by 1 unit. Its photoresponsivity (1300 A/W) can be tuned by ions in electrolyte. Photon absorption not only substantially reduced the response of intrinsic MoS2 by up to 95%, but also changed its sensing mechanism. After revealing the remarkable sensing performance of intrinsic MoS2, we demonstrated the possibility of the integration of MoS2 sensors functionalized with ionophore. Multiplex trace detection of Na+, Hg2+, and Cd2+ was realized on a 1 cm×1 cm chip with tunable sensitivity by illumination. The ion sensing results demonstrated outstanding selectivity, repeatability, detection limit (50 nM), response rate (10 s), and the capability of detecting target ions in environmental water samples. Our results show the prominent advantages of intrinsic MoS2 as a chemical sensing material.

At present, humidity sensors have promising prospects in disease monitoring, family life, environmental protection, and so on. Flexible humidity sensor is more and more popular because of its flexibility and portability. In our work, a flexible humidity sensor based on a tin disulfide (SnS2) nanoflower and a zinc stannate (Zn2SnO4) hollow sphere film was fabricated though layer-by-layer self-assembly technique. The humidity performance showed that the SnS2/Zn2SnO4 hybrid film sensor was ultrasensitive to humidity at room temperature. The test results demonstrated superior response, fast response/recovery behavior, and excellent repeatability. Moreover, compared to the single SnS2 and single Zn2SnO4 nanomaterials, the SnS2/Zn2SnO4 hybrid film sensor exhibited great improvement in humidity sensing. In addition, complex impedance spectroscopy was adopted to further explore the sensing mechanisms of the SnS2/Zn2SnO4 hybrid to various humidities. Human respiration, palm sweat, urine, and water droplets were de...

An ultrahigh-performance impedance-type humidity sensor based on tin disulfide (SnS2)/titanium dioxide (TiO2) nanocomposite was demonstrated via layer-by-layer self-assembly technique in this work. The nanostructures, morphologies, composition properties of the SnS2/TiO2 nanocomposite were fully examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The humidity sensing characteristics of the SnS2/TiO2 film sensor were investigated at room temperature. The results show that the SnS2/TiO2 film sensor has an impedance response up to 200050 and a sensitivity of 442000 Ω/%RH, which is much better than that of the existing humidity sensors. Excellent stability and repeatability are also exhibited for the SnS2/TiO2 film sensor. Moreover, the underlying sensing mechanism for the SnS2/TiO2 sensor toward humidity was explored with the complex impedance spectroscopy and the Bode diagram. The SnS2/TiO2 nanocomposite provides a promising building block for ultrahigh-sensitive humidity sensing and detection of human respiratory.

This paper reports a high-performance room-temperature ammonia gas sensor based on polyaniline/multi-walled carbon nanotubes/molybdenum disulfide (PANI/MWCNTs/MoS2) ternary nanocomposite prepared via in-situ chemical oxidative polymerization method. The component, morphology, crystallinity, and chemical state of PANI/MWCNTs/MoS2 sample was fully inspected by X-ray diffraction (XRD), fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS) and transmission electron microscope (TEM), confirming its successful fabrication and reasonability. The ammonia sensing properties of PANI/MWCNTs/MoS2 nanocomposite were investigated at room temperature. The experimental results exhibited excellent properties in terms of high response, fast response/recovery time as well as outstanding repeatability, which were greatly superior to the pure PANI, PANI/MWCNTs and PANI/MoS2 film counterparts. Finally, the potential ammonia-sensing mechanism of the PANI/MWCNTs/MoS2 nanocomposite was systematically discussed, which is attributed to the synergistic effect of the ternary nanomaterials and special interactions at p-n heterojunction.

Background Measurement-based care (MBC) is a popular strategy of clinical management for patients with major depressive disorder (MDD). The consistency of self-report and clinical measurements is of importance, but whether individual symptom severity is in agreement for both self-report and clinician rating in MDD has not been comprehensively tested. This study aimed to test whether individual symptom severity of MDD was in agreement between self-report and clinician rating, and to explore factors affecting the agreement. Methods In the National Survey on Symptomatology of Depression (NSSD) of China, 3275 patients with a major depressive episode were evaluated by both self-report and a clinician-rated version of 62 questions. Results On average, 59% of all patients reached absolute agreement with their research clinicians. Among all questions, 73% returned with moderate positive strength of correlation, followed by 27% with low positive correlation. In 77% of the total questions, there was a tendency to rate higher in the self-report version compared with the clinician-rated version. After classifying the symptoms by six major domains, it was found that patients and clinicians showed more consistent answers in history and somatic questions (81% and 65% reached agreement), and that there were more differences in mood, energy, and anxiety questions (up to 56% in full agreement). “Outpatient”, “high financial status”, “poor working condition”, and “high education level” were found to be significant positive predictors for patients rating higher than clinicians or patients and clinicians reaching agreement as opposed to clinicians rating higher than patients. Limitations The cross-sectional nature of our study undermines the interpretation of the results across the MDD treatment course. Conclusions It is sufficient to use the self-report version of a questionnaire to screen, monitor, and detect remission for MDD symptoms. Complete assessment of depression severity should take both clinician-rated scales and self-reported measures into consideration. Factors other than source of admission, financial status, working condition, and education level should be further investigated for the discrepancy between self-report and clinician rating.

Prediction of Meiyu withdrawal date (MWD) over the Yangtze-Huaihe River basin (YHRB) around mid-July has aroused extensive concern recently because of the profound socioeconomic and academic importance. However, relatively few researches have been carried out to identify the potential predictability source that can physically contribute to the Meiyu retreat over the YHRB, which exhibits profound year-to-year variations. This study identifies that the later-than-normal Meiyu withdrawal is preceded by the significant tropical June Arabian Sea (AS) surface sea surface (SST) warming on the interannual timescale. Analyses of possible mechanisms suggest that a striking quasi-barotropic “north-low–south-high” meridional seesaw pattern (i.e. PJ-like pattern) over the Northeast Asian–western North Pacific sector in July favors the transport and convergence of warm-moist water vapor and cold-dry air mass over the YHRB, inducing abundant in situ precipitation and thereby maintaining the Meiyu rainband. Under such a background, the Meiyu termination over the YHRB is delayed. Moreover, dynamical diagnoses and numerical model simulations indicate that the warmer-than-normal AS, which persists from June to the following July, can induce a notable localized low-level cyclonic anomaly via a Rossby-wave-like Matsuno–Gill-type atmospheric response. This cyclonic anomaly can further stimulate a large-scale atmosphere bridge stretching across South Asia and propagating poleward into Northeast Asia, which modulates the aforementioned downstream MWD-related atmospheric conditions continuously. Therefore, AS SST warming can remotely regulate and maintain the July Meiyu rainband through inducing a major direct forcing for the later Meiyu withdrawal over the YHRB, namely the East Asian coastal “north-low-south-high” meridional teleconnection. These results indicate and demonstrate the possible source of predictability for Meiyu withdrawal. This work may help improve forecasting of the withdrawal timing of Meiyu over the YHRB through more accurate predictions of SST over the AS region.

At present, humidity sensors have promising prospects in disease monitoring, family life, environmental protection, and so on. Flexible humidity sensor is more and more popular because of its flexibility and portability. In our work, a flexible humidity sensor based on a tin disulfide (SnS

Introduction Bioinformatic investigations indicate that has-mir-206 (microRNA-206, miRNA-206) could regulate BDNF protein synthesis by interfering with BDNF mRNA translation, which is disrupted in bipolar disorder (BPD). Objectives This study is to investigate whether miRNA-206 gene variants were associated with BPD susceptibility in a Han Chinese population. Methods 342 patients who met DSM-IV criteria for bipolar disorder type I (BPD-I) or type II (BPD-II) and 386 matched health controls were enrolled into this study. The miRNA-206 gene and +/-500bp were selected for gene sequencing. For the case-control genetic comparisons, differences in the genotype and allele distributions between patients and controls were examined using Pearson's χ 2 test. Results Gene sequencing showed that there are two polymorphisms rs16882131(C/T) and rs62408583 (A/C) located at the upstream of miRNA-206 gene, which are complete linkage disequilibrium. The association analysis showed that there was no significant difference for genotype frequencies (χ 2 = 2.075, df = 2, P = 0.354) or for allele frequencies (χ 2 = 0.041, df = 1, P = 0.839) between BPD patients and controls. Similarly, no significant difference was found between BPD-I patients and controls (genotype χ 2 = 1.411, df = 2, P = 0.494; allele χ 2 = 0.380, df = 1, P = 0.538). However, there was significant difference between BPD-II patients and controls (genotype χ 2 = 7.933, df = 2, P = 0.019; allele χ 2 = 5.403, df = 1, P = 0.020). Conclusions Our findings do not support that BPD susceptibility was associated with miRNA-206 gene polymorphisms in the studied Han Chinese population. The association between miRNA-206 gene polymorphisms and bipolar disorder type II is needed to be carefully interpreted. Further studies are necessary to elucidate the involvement miRNA-206 in the pathophysiology of BPD.