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Handwritten prescriptions are based on the thorough understanding of diseases and accurate diagnosis of patients by ancient Chinese physicians. This article discusses the particularities of TCM handwritten prescriptions in different historical periods in China, which are crucial to the study of contemporary medicine and calligraphy and the treatment of TCM diseases with their unique writing styles. We aim at study and summarize the evolution of ancient Chinese manuscripts from a historical perspective. As the only way to record the experience of disease diagnosis and treatment, in-depth research on handwritten prescriptions can open up new fields of scientific research in traditional Chinese medicine, promote the wide application and dissemination of ancient Chinese calligraphy works around the world, and provide more opportunities for future generations of medical references. This paper mainly adopts the survey method, literature review method, data analysis method, comparative analysis method and inductive summary method to conduct research, and strive to make the research convincing. Traditional Chinese medicine formulas are the empirical data of generations of doctors in meticulous diagnosis, investigation, prescription, dialectical treatment, and are a precious medical case. TCM has a long history in China, and it is an important foundation for TCM to treat diseases because of its good medicinal calligraphy styles. In-depth research has the potential to open up new areas of scientific research in Chinese medicine and encourage the widespread adaptation and dissemination of ancient Chinese calligraphy works worldwide. Its widespread use increases the number of references available for future medicine.

The hypothalamus is indispensable in energy regulation and glucose homeostasis. Previous studies have shown that pro-opiomelanocortin neurons receive both central neuronal signals, such as α-melanocyte-stimulating hormone, β-endorphin, and adrenocorticotropic hormone, as well as sense peripheral signals such as leptin, insulin, adiponectin, glucagon-like peptide-1, and glucagon-like peptide-2, affecting glucose metabolism through their corresponding receptors and related signaling pathways. Abnormalities in these processes can lead to obesity, type 2 diabetes, and other metabolic diseases. However, the mechanisms by which these signal molecules fulfill their role remain unclear. Consequently, in this review, we explored the mechanisms of these hormones and signals on obesity and diabetes to suggest potential therapeutic targets for obesity-related metabolic diseases. Multi-drug combination therapy for obesity and diabetes is becoming a trend and requires further research to help patients to better control their blood glucose and improve their prognosis.

BACKGROUND Multiple studies demonstrate that fluctuating blood glucose level produces greater damage compared with sustained hyperglycemia. Flash glucose monitoring system is an effective method in documenting blood glucose variability, contributing to better glucose management and reduced hypoglycemic event occurrence. AIM To investigate the improvement in glycemic variability (GV), blood glucose level, and metabolic indexes of patients with type 2 diabetes mellitus after combined treatment of exenatide once weekly (EXQW) and metformin. METHODS Twenty-five patients with type 2 diabetes mellitus suffering from poor blood glucose control under metformin treatment were recruited. The recruited patients were prescribed with oral metformin only (maintaining a dosage of metformin at ≥ 1500 mg/day) for 2 wk (screening period), and then given EXQW (2 mg, subcutaneous injection) for 12 wk (experimental period). The flash glucose monitoring system was used to document blood glucose values during the screening period and the last 2 wk of the experimental period. RESULTS Four patients were excluded for various reasons, yielding a total of 21 patients, including 17 males and 4 females, with an average age of 48.8 years, who completed this study. The estimated glycated hemoglobin, mean blood glucose, fasting and postprandial blood glucose levels, and percentage of blood glucose above 7.8 mmol/L decreased compared to those at baseline (P = 0.003, 0.003, 0.008, 0.010, 0.014, 0.017, and 0.005, respectively), while the percentage of blood glucose between 3.9 and 7.8 mmol/L significantly increased (P = 0.005). Parameters of GV including standard deviation of blood glucose, mean amplitude of glycemic excursions, mean of daily difference, area under the curve difference between percentiles 25 and 75, and area under the curve difference between percentiles 10 and 90 were significantly lower compared to that of baseline (P = 0.017, 0.006, 0.000, 0.024, 0.036, respectively). The durations of blood glucose below 3.9 mmol/L during the day and nocturnal periods significantly increased after treatment (P = 0.041 and 0.028, respectively), but there was no significant increase in severe hypoglycemia (< 3.0 mmol/L) compared with that at baseline (P = 0.207). In addition, some metabolic indicators improved after EXQW treatment. CONCLUSION EXQW combined with metformin can effectively improve blood glucose levels, reduce GV, and improve metabolic indicators. However, there is still a risk of nocturnal hypoglycemia, and careful attention should be paid to patients with EXQW treatment.

Here, we report a case of a patient with symptoms of Cushing syndrome, who is diagnosed with primary generalized glucocorticoid hypersensitivity in the end. The patient's relevant laboratory tests and imaging examinations are described. Mifepristone, a glucocorticoid receptor antagonist, was prescribed and its therapeutic effect on the patient's electrolyte level, lipid metabolism, and bone metabolism was observed during the treatment. The endocrine assessment indicated normal pituitary-adrenal axis regulation function but reduced cortisol secretion. Quantitative reverse transcription-polymerase chain reaction indicated reduced mRNA level of mineralocorticoid receptor gene. Pituitary magnetic resonance imaging showed normal pituitary anatomy, while adrenal computed tomography scan showed bilateral adrenal atrophy and increased content of visceral and abdominal subcutaneous fat. Moreover, chromosome examination revealed a normal 46, XY chromosome. In this case, mifepristone was administered to treat primary generalized glucocorticoid hypersensitivity. To the best of our knowledge, there are a few reports on mifepristone-treated primary generalized glucocorticoid hypersensitivity. In the one-year follow-up visits, the evaluated results of electrolyte level, lipid metabolism, and bone metabolism indicated that the patient's symptoms resulting from cortisol hypersensitivity were relieved progressively.

Coexistence of congenital adrenal hyperplasia due to 21-hydroxylase deficiency, Graves' disease and 47, XXX is rare. We report a case of a 25-year-old woman presented with masculine appearance, hirsutism and enlarged clitoris. Lab tests showed elevated serum 17 hydroxyprogesterone, testosterone, dehydroepiandrosterone. Gene test revealed heterozygous gene mutation in CYP21A2:NM_000500:exon4:c.518 T A, NM_000500:exon8:c.C1024T. Karyotype analysis showed 47, XXX. After prednisone replacement and antithyroid therapy, she got a normal menstruation and normal level of testosterone. These findings demonstrate that patients with abnormal chromosome are likely to combine 21-hydroxylase deficiency (21-OHD), thus karyotyping test should not be neglected for those who have been already diagnosed as 21-OHD. Additionally, chromosomal abnormality such as 47, XXX and Turner syndrome had susceptibility to develop autoimmune thyroid disease because a gene on X chromosome may be responsible for the occurrence of autoimmune thyroid disease. Moreover, both 21-OHD and Graves' disease (GD) can lead to high level of testosterone, thus we should keep in mind to test chromosome and thyroid function in 21-OHD patients to avoid misdiagnose or missed diagnosis. To the best of our knowledge, this is the first report of simple virilizing (SV) 21-OHD patient combined with 47, XXX and Graves disease.A 24-years-old female of Han ethnicity was admitted to the endocrinology department complaining of absence of menses for half a year. The patient didn't noticed her enlarged clitoris until she was 17 years old. Her menarche was 16 years old and the final height was 163 centimeter. She was diagnosed with GD 2 months before admission to our hospital due to palpitation, heat intolerance, muscle weakness.The patient was diagnosed with SV 21-OHD, Graves disease and 47, XXX.At first, the patient was given 10 mg methimazole twice a day as well as 5 mg predisone in the morning and 2.5 mg in the evening. After a year of regular medication and reexamination, she got a regular menstruation and thyroid function and now is taking 2.5 mg prednisone twice a day.The patient got a regular menstruation and thyroid function. Laboratory results showed: testosterone declined to 0.1nmol/L (0.1-1.67nmol/L) and 17 hydroxyprogesterone get back to normal level: 1.01ng/ml (0.30-2.34ng/mL). However, her enlarged clitoris has not narrowed.Patients with abnormal chromosome are likely to combine 21-OHD, thus karyotyping test should not be neglected for those who have been already diagnosed as 21-OHD. Additionally, chromosomal abnormality such as 47, XXX and Turner syndrome had susceptibility to develop autoimmune thyroid disease because a gene on X chromosome may be responsible for the occurrence of autoimmune thyroid disease. Moreover, both 21-OHD and GD can lead to high level of testosterone, thus we should keep in mind to test chromosome and thyroid function in 21-OHD patients to avoid misdiagnose or missed diagnosis. To the best of our knowledge, this is the first report of SV 21-OHD patient combined with 47, XXX and Graves disease.

BackgroundIncome level is an important factor that influences the occurrence of gestational diabetes. Thus, this systematic review and network meta-analysis aimed at evaluating the correlation between income levels and the prevalence of gestational diabetes. MethodsRelevant published studies were searched in Pubmed, Web of Science, Cochrane library, and Ovid from the establishment time of database to January 3, 2020. Finally, 13 eligible clinical studies involving 1,817,801 women were selected from a total of 3776 studies and included in this study. The statistical softwares Revman5.3 and Stata14.0 were used to compare the prevalence of gestational diabetes in five different income levels; low, lower middle, medium, upper middle, and high. ResultsThe incidences of gestational diabetes in people with different economic income levels were: high income

Background Congenital adrenal hyperplasia (CAH) with 17α-hydroxylase deficiency is a rare disease; patients often require lifetime cortisol treatment. In this case report, we presented a patient with CAH and 17α-hydroxylase deficiency, who was previously misdiagnosed as having primary aldosteronism. Furthermore, the flash glucose monitoring system (FGMS) was used to ascertain a suitable cortisol therapeutic regimen for this patient. Case presentation A 29-year-old woman presented with sex dysgenesis, hypertension and hypokalaemia. She had been diagnosed with primary aldosteronism at a local hospital. The re-measured aldosterone level in our hospital was below the normal range after antihypertensive medication adjustment, suggesting that the primary aldosteronism was a misdiagnosis. The patient was finally diagnosed as having CAH with 17α-hydroxylase deficiency according to the endocrine profile, adrenocorticotropic hormone stimulation test, and genetic analysis. Then, the patient was recommended cortisol treatment, during which the endocrine profile, blood pressure, plasma potassium level, and blood glucose level were observed to ascertain a suitable dosage. The FGMS was used to monitor blood glucose level, which indicated that the patient’s glucose metabolism was maintained normally under the final treatment dosage. Conclusion The misdiagnosis might have been because of the effects of the antihypertension medications on aldosterone and renin levels. The final dosage of cortisol treatment achieved a normal endocrine profile, while maintaining the homeostasis of blood glucose level, plasma potassium level and blood pressure. FGMS may be an effective method to ascertain a suitable cortisol therapeutic regimen for patients with CAH and 17α-hydroxylase deficiency.

In this work, the structural and mechanical properties, tribological performance, and lubrication mechanism from room temperature to 900 °C of TiN/MoS2/Ag composite films were investigated in detail. Nanostructured TiN/MoS2/Ag composite film was obtained by assembling targets using pulsed laser deposition. The incorporation of lubricant layered MoS2 and soft metal Ag led to degraded mechanical properties, which could contribute to the lower friction coefficients at low temperatures. When the temperature increased to above 500 °C, the generated high-temperature lubricant MoO3 and silver molybdates played a critical synergetic lubrication effect, which formed a layer of lubricating film and reduced the friction coefficient. Thus, the cooperation of various lubrication phases contributed to improvement of tribological performance and resulted in continuous lubrication from room temperature to 900 °C.

The motion resistance and energy dissipation of rolling friction are much lower than those of sliding friction at the macroscale. But at the microscale, the impact of rolling on friction remains an open question. Here, we show that spherical MoS2 nanoparticles can be formed in situ at a friction interface by scrolling and wrapping MoS2 nanosheets under the induction of a reciprocating shear stress, when an MoS2 coating constructed from loosely stacked nanosheets is tested in a vacuum of 3.5 × 10−3 Pa. An ultra-low friction state can be readily realized with friction coefficients of 0.004–0.006, which are one order of magnitude lower than that of a pulse laser deposited MoS2 coating without nanoparticles formed in a friction process. Accordingly, the spherical nanoparticles are highlighted as the key factor in the ultra-low friction. Classical molecular dynamics simulations further reveal that the motion mode of the MoS2 nanoparticle is stress-dependent. This finding confirms access to ultra-low friction by introducing rolling friction based on the microstructural evolution of the coating.

Herein, we report a facile template-free solvothermal chemical method to synthesize the hierarchical hollow CuSbS2 microspheres. The results show that the hollow microspheres with the diameter of ~800–900 nm are comprised of nanoflakes. The morphologies of CuSbS2 can be modulated rationally by adjusting the reaction parameters and the possible formation mechanism of hollow CuSbS2 microspheres with PSS (poly (sodium-p-styrenesul-fonate)) and PEG (polyethylene glycol) is studied. Moreover, the hollow CuSbS2 microspheres exhibits a photocurrent density of 0.063 mA/cm2 and an IPCE value of 32.42%, indicating that the CuSbS2 nanocrystals have potential in photoelectrochemical conversion device applications.

The NiCrAlY-Mo-Ag composite was fabricated by vacuum hot-pressing sintering. The friction and wear behaviour of the composite were investigated from room temperature to 900 °C. Furthermore, the wear mechanism was studied over this wide range of temperatures. At the same time, the compressive properties of the composite were researched. The composition and microstructure of the composite were analyzed by X-ray diffraction (XRD) and scanning election microscopy (SEM). At 700 °C and 900 °C, the tribo-chemical reaction occurred on the worn surface and formed a high-temperature tribo-layer based on NiO and silver molybdates, which could effectively reduce the friction coefficient and wear rate of the composite. The existence of broken particles and the pullout of hard phase particles were seen on the fracture surface of the composite, which were determined by the interfacial bonding strength.

The conventional and nanostructured NiCrAlY-Mo-Ag composite coatings were prepared by atmospheric plasma spraying so as to make the hot parts achieve and maintain excellent tribological properties at elevated temperature of up to 900 °C. The microstructure, mechanical and tribological properties of these two composite coatings were investigated and compared. The X-ray diffraction (XRD), micro-Raman, scanning election microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze the composition and microstructure of the composite coatings. Results show that the nanostructured composite coating presented higher microhardness and adhesive strength than conventional composite coating. Meanwhile, the nanostructured composite coating had less defects, lower porosity, more compact microstructure and smaller grains as compared to the corresponding conventional coating which was useful to improve the performance of the composite coating. The nanostructured composite coating possessed better tribological properties as compared with the conventional composite coating. The sliding process could promote the tribo-chemical reaction between silver, nickel and molybdenum to form silver molybdates and nickel molybdates lubricating films on the worn surface at high temperature. The silver molybdates and nickel molybdates could also enhance tribological properties of composite coatings at high temperature.

The NiAl-Mo-Ag and NiAl-Cr2O3-Mo-Ag composite coatings were fabricated by atmospheric plasma spraying with the substrate material of Inconel 718. The effect of heat treatment on the microstructure, adhesive strength, microhardness and tribological properties of NiAl-Cr2O3-Mo-Ag composite coating was investigated. The heat treatment temperatures were chosen as 400, 500 and 600 °C. The composition and microstructure of composite coatings were analyzed by X-ray diffraction (XRD), scanning election microscopy (SEM) and transmission electron microscopy (TEM). The results show that the addition of Cr2O3 could effectively reduce the wear rate of NiAl-Mo-Ag composite coating. The adhesive strength, microhardness and tribological properties of NiAl-Cr2O3-Mo-Ag composite coating were improved by heat treatment. After 500 °C heat treatment, the microstructure of composite coating became more homogeneous and the coating had the highest adhesive strength, microhardness and the best tribological properties. The sliding process could promote the silver, nickel and molybdenum occur tribo-chemical reaction to form silver molybdates and nickel molybdates lubricating films which were responsible for the good tribological properties of composite coatings at elevated temperatures.

The NiAl matrix composite coatings containing silver and molybdenum were prepared by atmospheric plasma spraying and their tribological properties were investigated in details from 25 to 900 °C. The X-ray diffraction (XRD), micro-Raman, scanning election microscopy (SEM) and transmission election microscopy (TEM) were used to analyze the composition and microstructure of composite coatings. The X-ray diffraction (XRD) results shown that molybdenum and silver were exist in single-phase, but not alloyed in composite coatings. The addition of silver could effectively improve the tribological properties of composite coatings at the wide range of temperature. The silver, nickel and molybdenum could occur the tribo-chemical reaction and form silver molybdates and nickel molybdates lubricating films inside the wear track of composite coatings at high temperature. The friction process promoted the formation of the silver molybdates. The silver molybdates, nickel molybdates and NiO were the main components in composite coatings at high temperature, which could effectively improve tribological properties of composite coatings.

The NiCrAlY–Mo–Ag composite coatings were prepared by atmospheric plasma spraying. The tribological properties of the composite coatings were investigated from 25 to 900 °C in details. The tribo-layer formed on the worn surface of the composite coatings and influenced the tribological properties at different temperatures. The addition of silver could effectively decrease the friction coefficient and wear rate of the coatings at the wide range of temperature. The rubbing process could form the nickel molybdate and promote the formation of silver molybdate within the worn surfaces at high temperature. The synergistic lubricating effects of nickel molybdate and silver molybdate are attributed to the improvement of the tribological properties of coatings at high temperature.

The VN/Ag composite films with various silver content were prepared by PLD technique, and the microstructures, mechanical and tribological properties at elevated temperature to 900 °C of films were investigated, respectively. The results show that the films were composed of the fcc VN and Ag nano-crystalline grains. With the increase of silver content from 8.2 to 56.1 at.%, the grain size increased and the surface morphology deteriorated gradually, the hardness and elastic modulus of the films decreased from 18.6 GPa, 226.3 GPa–8.1 GPa, 126.6 GPa, respectively. Only appropriate silver addition could improve the lubricity of the VN/Ag films. The film with 16.6 at.% Ag were found to be optimized for lubrication from RT to 900 °C. At low temperatures, the lubricant property of the film relied on the metal silver heavily. At elevated temperatures, a series of Magneli phase (vanadium oxides) and the layered structure silver vanadates (such as Ag3VO4, AgVO3) formed by tribochemical reactions in the contact area played a critical role in improving lubrication properties. A synergy of the lubricating Ag at low temperatures and the new lubrication phases generated at high temperatures could be responsible to the excellent lubricity of the VN/Ag films in wide temperature range.

In this work, the pulsed laser deposition (PLD) technique is applied for direct physical deposition of narrow bandgap semiconductor Bi2S3 quantum dots (QDs) on one-dimensional TiO2 nanorod arrays to fabricate quantum dots sensitized solar cells (QDSSCs). Without regard for any protective packaging or surface treatment process for binding QDs, the QDSSCs exhibit excellent stability and high energy conversion efficiency in ambient air. Through varying the laser ablation pulses, the controlled coverage of QDs on nanorods is realized and an optimal energy conversion efficiency of 3.06% is obtained under one sun illumination (AM 1.5, 100 mW cm−2). The enhanced absorption in an extended wavelength range, quick interfacial charge transfer and few recombination chances for electrons with holes are believed to contribute to the improved performance of Bi2S3 QD-sensitized solar cells. Moreover, a sputtered plasma at high velocity can collide intensely with the surface of TiO2, which enables direct atomic contact and endows the QDSSCs with high stability. These promising results provide a potential option of using the PLD technique for the fabrication of QD-based solar cells or other thin film photo-absorption materials.

A novel 3D cross-linked heterostructure of TiO2 nanorods connecting with each other via ultrathin Bi2S3 nanosheets is constructed by a facile and effective strategy. The growth mechanism has been investigated and proposed based on the evolution of microstructure by changing the reaction parameters. Benefiting from the unique cross-linked heterostructure, the as-prepared Bi2S3 nanosheets modified TiO2 nanorods arrays could achieve a high energy conversion efficiency of 3.29% which is the highest value to date for Bi2S3-only sensitized solar cells as the reported highest value is 2.23% and other reported values are less than 1%. Furthermore, the photoelectrochemical studies clearly reveal that the novel cross-linked heterostructure exhibits much better activity than 0D nanoparticles decorated TiO2 nanorods under visible light irradiation, which may be primarily ascribed to the efficient electron transfer from 2D ultrathin Bi2S3 nanosheets to 1D TiO2 nanorod arrays. The promising results in this work confirm the advantages of cross-linked heterostructure and also undoubtedly offer an attractive synthesis strategy to fabricate other nanorod-based hierarchical architecture as well as nano-devices for solar energy conversion.

In order to avoid the impurity phase, such as Ag 3 SbS 3 and Sb 2 S 3 among AgSbS 2 particles and simplify the complicated steps in synthesizing AgSbS 2 via conventional methods, the cubic AgSbS 2 silk-like nanoflowers with well-defined crystalline structure were synthesized by the one-step, facile and practical solvothermal chemical process. The results show that the as-prepared stoichiometric AgSbS 2 nanoflowers with the diameter of 1 µm are comprised of silk-like ultrathin nanoflakes. Moreover, the possible formation mechanism of AgSbS 2 silk-like nanoflowers with PSS (poly (sodium-p-styrenesul-fonate)) is studied. Furthermore, the AgSbS 2 nanoflowers exhibit a broad absorption and high value of incident photon to current conversion efficiency (IPCE) in visible light range, indicating that it is a promising photovoltaic absorption material.

In the typical solution-based synthesis of colloidal quantum dots (QDs), it always resorts to some surface treatment, ligand exchange processing or post-synthesis processing, which might involve some toxic chemical regents injurious to the performance of QD sensitized solar cells. In this work, the CuInS2 QDs are deposited on the surface of one-dimensional TiO2 nanorod arrays by the pulsed laser deposition (PLD) technique. The CuInS2 QDs are coated on TiO2 nanorods without any ligand engineering, and the performance of the obtained CuInS2 QD sensitized solar cells is optimized by adjusting the laser energy. An energy conversion efficiency of 3.95% is achieved under one sun illumination (AM 1.5, 100 mW cm−2). The improved performance is attributed to enhanced absorption in the longer wavelength region, quick interfacial charge transfer and few chance of carrier recombination with holes for CuInS2 QD-sensitized solar cells. Moreover, the photovoltaic device exhibits high stability in air without any specific encapsulation. Thus, the PLD technique could be further applied for the fabrication of QDs or other absorption materials.

We firstly fabricated a peculiar 3D structure of Bi2S3 salix leaf-like nanosheet/TiO2 nanorod branched heterostructure arrays by a convenient hydrothermal method and discussed their mechanism of improving photoelectrochemical cell (PEC) properties. The salix leaf-like Bi2S3 nanosheets (NSs) were grown on TiO2 nanorod arrays through controlling the molar ratio of EDTA-Na2/Bi3+ and the reaction time. The morphology, crystal structure, microstructure and optical performance of the 3D Bi2S3 NS/TiO2 NRs at different reaction times were investigated. The results show that the branched heterostructure of 3D Bi2S3 NS/TiO2 NR arrays exhibits enhanced photocurrent density and optical absorption, which were attributed to the larger Bi2S3 surface area, as well as a direct electron path within the salix leaf-like Bi2S3 NS and TiO2 NR heterojunctions, resulting from more excitation sites of incident light. The photocurrent density of the 3D Bi2S3 NS/TiO2 NR arrays was almost 9 times greater than that of pristine TiO2 without a branching structure. The results of the present work demonstrate that fabrication of the branched Bi2S3 NS/TiO2 NR heterogeneous structure is a significant fabrication technology with great promise in PECs.

The PLD technique is used for the direct fabrication of QD sensitized solar cells (QDSSCs) without any encapsulation and/or resorting to any surface treatment, ligand engineering and/or post-synthesis processing which might involve some toxic chemical regents harmful to the performance of solar cells. In this paper, co-sensitizers of Bi2S3 and CuInS2 quantum dots (QDs) are deposited on TiO2 nanorods via a physical deposition-based pulsed laser deposition (PLD) technique to fabricate the cascade structure of Bi2S3/CuInS2/TiO2. The performance of the QDSSCs with a cascade structure is optimized by adjusting the laser energy, and an energy conversion efficiency of 4.81% is achieved under one sun illumination (AM 1.5, 100 mW cm−2). Besides, the photovoltaic device exhibits high stability in air without any specific encapsulation. The improved performance is attributed to enhanced absorption in the longer wavelength region, quicker interfacial charge transfer and less chance of electron recombination with holes. Moreover, the direct atomic contact by the PLD technique and the cascade structure are also favorable factors for the enhanced photoelectrochemical performance of QDSSCs.

Abctract High quality ternary chalcogenide AgSbS 2 nanospheres have been synthesized via a one-step, facile and practical solvothermal chemical process by using 3-aminopropyl triethoxysilane(APTS) self-assembly monolayers(SAMs) as templates. The surface morphology, structure and composition of the resultant AgSbS 2 nanospheres were characterized by FESEM, XRD and XPS, respectively. The results show that the nearly stoichiometric AgSbS 2 nanospheres possess pure cubic structure with high crystallinity. The –NH 2 terminal groups of APTS could provide nucleation sites for the growth of AgSbS 2 nanospheres and the slow release of Sb 3+ in the solution could promote the isotropic growth of AgSbS 2 crystal. AgSbS 2 nanospheres exhibit a broad absorption in visible light range, making it a promising photovoltaic absorber material.

Ferroelectric perovskite oxides [KNbO 3 ] 1−x [BaCo 1/2 Nb 1/2 O 3−δ ] x (KBCNO, δ>0 means the existence of oxygen vacancies) solid solutions (0.1≤x≤0.5)were successfully synthesized by doping Co and Ba into the lattice of KNbO 3 though solid-state reaction. The band gap energy of KBCNO shifts down to 2.4 eV and became visible-light-active due to the doping affection on the energy band structure comparing with that of wide-band-gap semiconductor KNbO 3 (3.4 eV). The X-ray diffraction and Raman spectra revealed that the KBCNO solid solutions are in perovsite phase and gradually transiting from orthorhombic to cubic structure with the different BaCo 1/2 Nb 1/2 O 3−δ (BCNO) contents. The reduction of band gap value makes KBCNO ferroelectric a promising candidate for photovoltaic materials.

The motion resistance and energy dissipation of rolling friction are much lower than those of sliding friction at the macroscale. But at the microscale, the impact of rolling on friction remains an open question. Here, we show that spherical MoS2 nanoparticles can be formed in situ at a friction interface by scrolling and wrapping MoS2 nanosheets under the induction of a reciprocating shear stress, when an MoS2 coating constructed from loosely stacked nanosheets is tested in a vacuum of 3.5 × 10-3 Pa. An ultra-low friction state can be readily realized with friction coefficients of 0.004-0.006, which are one order of magnitude lower than that of a pulse laser deposited MoS2 coating without nanoparticles formed in a friction process. Accordingly, the spherical nanoparticles are highlighted as the key factor in the ultra-low friction. Classical molecular dynamics simulations further reveal that the motion mode of the MoS2 nanoparticle is stress-dependent. This finding confirms access to ultra-low friction by introducing rolling friction based on the microstructural evolution of the coating.

TiO2/CuInS2/Bi2S3 core/shell/shell (CSS) nanorods (NRs) electrodes were synthesized by the successive ionic layer adsorption and reaction (SILAR) method and applied as the photoelectrodes for high performance in a photoelectrochemical (PEC) cell, wherein the narrow bandgap non-toxic materials, CuInS2 and Bi2S3, were selected to expand the light absorption range to the near-infrared region. The uniform Bi2S3 layer was directly covered on the previously coated CuInS2 layer on TiO2 NRs to prevent the polysulfide electrolytes' corrosion of CuInS2. The morphology, crystal structure, optical properties and PEC performance of plain TiO2, single TiO2/CuInS2 core/shell (CS) and TiO2/CuInS2/Bi2S3 CSS NRs were investigated in detail. The deposition cycles of CuInS2 and Bi2S3 on TiO2 NRs were optimized to enhance the PEC performance of TiO2/CuInS2/Bi2S3 CSS composites electrodes. The results show that TiO2/CuInS2/Bi2S3 CSS obtained enhanced photoconversion efficiency (6 times higher than that of plain TiO2 and 1.5 times than TiO2/CuInS2 CS). Therefore, the construction of CSS nanostructured composites electrodes through coupling single core/shell nanostructures with another narrow gap semiconductor shell suggests a promising design for improving the absorption efficiency and PEC performance of photoelectrodes.