[Expressions of zinc homeostasis proteins, GPR39 and ANO1 mRNA in the sperm of asthenozoospermia patients and their clinical significance].

OBJECTIVE: To explore the expressions of zinc homeostasis-related proteins, G protein-coupled receptor 39 (GPR39) and ANO1 mRNA in the sperm of patients with asthenozoospermia (AS), and analyze their correlation with sperm motility. METHODS: We collected semen samples from 82 male subjects with PR+NP < 40%, PR < 32% and sperm concentration > 15×106/ml (the AS group, n = 40) or PR+NP ≥ 40%, PR ≥ 32% and sperm concentration > 15×106/ml (the normal control group, n = 42). We analyzed the routine semen parameters and measured the zinc content in the seminal plasma using the computer-assisted sperm analysis system, detected the expressions of zinc transporters (ZIP13, ZIP8 and ZNT10), metallothioneins (MT1G, MT1 and MTF), GPR39, and calcium-dependent chloride channel protein (ANO1) in the sperm by real-time quantitative PCR (RT qPCR), examined free zinc distribution in the sperm by laser confocal microscopy, and determined the expressions of GPR39 and MT1 proteins in the sperm by immunofluorescence staining, followed by Spearman rank correlation analysis of their correlation with semen parameters. RESULTS: There was no statistically significant difference in the zinc concentration in the seminal plasma between the AS and normal control groups (P>0.05). Compared with the controls, the AS patients showed a significantly reduced free zinc level (P<0.05), relative expressions of MT1G, MTF, ZIP13, GPR39 and ANO1 mRNA (P<0.05), and that of the GPR39 protein in the AS group (P<0.05). No statistically significant differences were observed in the relative expression levels of ZIP8, ZNT10 and MT1 mRNA between the two groups (P>0.05). The relative expression levels of GPR39, ANO1, MT1G and MTF mRNA were positively correlated with sperm motility and the percentage of progressively motile sperm (P<0.05). CONCLUSION: The expressions of zinc homeostasis proteins (MT1G, MTF and ZIP13), GPR39 and ANO1 mRNA are downregulated in the sperm of asthenozoospermia patients, and positively correlated with sperm motility.

The relationship between family function and the incidence of overweight/obesity in children and adolescents in Chengdu city, Sichuan province of China: based on latent profile analysis.

BACKGROUND: Overweight/obesity in children and adolescents has become a global health problem, and family function may be associated with its occurrence. Studies exploring the association between family function and overweight/obesity in children and adolescents were performed in Western and Taiwan, China. To date, related studies haven't been conducted in Mainland China. OBJECTIVES: To investigate the current status of overweight, obesity, and family function among children and adolescents in Chengdu, China, and to explore their associations. METHODS: Children and adolescents in five primary and middle schools were chosen by cluster sampling. Body Mass Index was used to measure the status of overweight and obesity, and the Chinese family assessment instrument was adopted to assess family function. Latent profile analysis and stepwise logistic regression were applied to identify family classification and explore the relationships between family function and overweight/obesity. RESULTS: A total of 7616 (84.92%) children and adolescents out of 8968 completed the study with qualified-filled questionnaires. Nine hundred and sixty-six (12.68%)participants were overweight and 656 (8.61%) were obese. The family function was categorized into three profiles: mild (63.93%), moderate (12.32%), and severe (23.75%) dysfunction. The prevalence of overweight was 12.16%, 14.71%, and 13.05% for mild, moderate, and severe family dysfunction, respectively. And the prevalence of obesity was 8.19%, 10.77%, and 8.62% respectively. Participants in moderate and severe dysfunction families were more likely to be overweight (moderate: OR = 1.27, 95% CI:1.01 ~ 1.59, P = 0.04; severe: OR = 1.38, 95% CI:1.15 ~ 1.66, P = 0.001) and obese (moderate: OR = 1.35, 95% CI:1.02 ~ 1.79, P = 0.03; severe: OR = 1.55, 95% CI:1.23 ~ 1.96, P < 0.001). Sociodemographic data such as gender, residence, grade, pocket money per week, the number of siblings, and the education level of the mother were all associated with the risk of being overweight/obese in children and adolescents. CONCLUSIONS: The problems of being overweight or obese exist among children and adolescents in Chengdu. And the risk of being overweight or obese increases along with the decrease in family function.

Preparation of a High-Silicon ZSM-5 Molecular Sieve Using Only Coal Gangue as the Silicon and Aluminum Sources.

The traditional preparation of ZSM-5 molecular sieves relies on chemical reagents to provide silicon and aluminum sources, which are limited as raw materials and cannot be commonly used in production practice. Using coal gangue as the raw material and using medium-temperature chlorination roasting and the pressure acid leaching process to control the silicon-aluminum ratio [n(Si/Al)] of coal gangue, a ZSM-5 molecular sieve was prepared using the alkali melting hydrothermal method. The pressure acid leaching process solved the limitation that kaolinite and mica cannot simultaneously be activated. Under optimal conditions, the n(Si/Al) of the coal gangue increased from 6.23 to 26.14 and complied with the requirements for the synthesis n(Si/Al) of a ZSM-5 molecular sieve. The effect of n(Si/Al) on the preparation of the ZSM-5 molecular sieve was studied. Finally, spherical granular ZSM-5 molecular sieve material with a microporous specific surface area of 169.6329 m2/g, an average pore diameter of 0.6285 nm, and a pore volume of 0.0988 cm3/g was prepared. Providing ideas for the high-value utilization of coal gangue, it is significant for solving the problem of coal gangue solid waste, as well as the problem of ZSM-5 molecular sieve feed stock.

Wavelength-Tunable Narrow-Linewidth Laser Diode Based on Self-Injection Locking with a High-Q Lithium Niobate Microring Resonator.

We demonstrate a narrow linewidth 980 nm laser by self-injection locking of an electrically pumped distributed-feedback (DFB) laser diode to a high quality (Q) factor (>105) lithium niobate (LN) microring resonator. The lithium niobate microring resonator is fabricated by photolithography-assisted chemo-mechanical etching (PLACE) technique, and the Q factor of lithium niobate microring is measured as high as 6.91 × 105. The linewidth of the multimode 980 nm laser diode, which is ~2 nm measured from its output end, is narrowed down to 35 pm with a single-mode characteristic after coupling with the high-Q LN microring resonator. The output power of the narrow-linewidth microlaser is about 4.27 mW, and the wavelength tuning range reaches 2.57 nm. This work explores a hybrid integrated narrow linewidth 980 nm laser that has potential applications in high-efficient pump laser, optical tweezers, quantum information, as well as chip-based precision spectroscopy and metrology.

On-Chip Integrated Yb3+-Doped Waveguide Amplifiers on Thin Film Lithium Niobate.

We report the fabrication and optical characterization of Yb3+-doped waveguide amplifiers (YDWA) on the thin film lithium niobate fabricated by photolithography assisted chemo-mechanical etching. The fabricated Yb3+-doped lithium niobate waveguides demonstrates low propagation loss of 0.13 dB/cm at 1030 nm and 0.1 dB/cm at 1060 nm. The internal net gain of 5 dB at 1030 nm and 8 dB at 1060 nm are measured on a 4.0 cm long waveguide pumped by 976 nm laser diodes, indicating the gain per unit length of 1.25 dB/cm at 1030 nm and 2 dB/cm at 1060 nm, respectively. The integrated Yb3+-doped lithium niobate waveguide amplifiers will benefit the development of a powerful gain platform and are expected to contribute to the high-density integration of thin film lithium niobate based photonic chip.

High-Production-Rate Fabrication of Low-Loss Lithium Niobate Electro-Optic Modulators Using Photolithography Assisted Chemo-Mechanical Etching (PLACE).

Integrated thin-film lithium niobate (LN) electro-optic (EO) modulators of broad bandwidth, low insertion loss, low cost and high production rate are essential elements in contemporary interconnection industries and disruptive applications. Here, we demonstrated the design and fabrication of a high performance thin-film LN EO modulator using photolithography assisted chemo-mechanical etching (PLACE) technology. Our device shows a 3-dB bandwidth over 50 GHz, along with a comparable low half wave voltage-length product of 2.16 Vcm and a fiber-to-fiber insertion loss of 2.6 dB. The PLACE technology supports large footprint, high fabrication uniformity, competitive production rate and extreme low device optical loss simultaneously, our result shows promising potential for developing high-performance large-scale low-loss photonic integrated devices.

Laser diode-pumped compact hybrid lithium niobate microring laser.

We demonstrate a compact hybrid lithium niobate microring laser by butt coupling a commercial 980-nm pump laser diode chip with a high-quality Er3+-doped lithium niobate microring chip. Single-mode lasing emission at 1531-nm wavelength from the Er3+-doped lithium niobate microring can be observed with the integrated 980-nm laser pumping. The compact hybrid lithium niobate microring laser occupies the chip size of 3 mm × 4 mm × 0.5 mm. The threshold pumping laser power is 6 mW and the threshold current is 0.5 A (operating voltage 1.64 V) at atmospheric temperature. The spectrum featuring single-mode lasing with small linewidth of 0.05 nm is observed. This work explores a robust hybrid lithium niobate microring laser source which has potential applications in coherent optical communication and precision metrology.

An Ultra-High-Q Lithium Niobate Microresonator Integrated with a Silicon Nitride Waveguide in the Vertical Configuration for Evanescent Light Coupling.

We demonstrate the hybrid integration of a lithium niobate microring resonator with a silicon nitride waveguide in the vertical configuration to achieve efficient light coupling. The microring resonator is fabricated on a lithium niobate on insulator (LNOI) substrate using photolithography assisted chemo-mechanical etching (PLACE). A fused silica cladding layer is deposited on the LNOI ring resonator. The silicon nitride waveguide is further produced on the fused silica cladding layer by first fabricating a trench in the fused silica while using focused ion beam (FIB) etching for facilitating the evanescent coupling, followed by the formation of the silicon nitride waveguide on the bottom of the trench. The FIB etching ensures the required high positioning accuracy between the waveguide and ring resonator. We achieve Q-factors as high as 1.4 × 107 with the vertically integrated device.

Efficient light coupling between an ultra-low loss lithium niobate waveguide and an adiabatically tapered single mode optical fiber.

A lithium niobate on an insulator ridge waveguide allows constructing high-density photonic integrated circuits thanks to its small bending radius offered by the high index contrast. Meanwhile, the significant mode-field mismatch between an optical fiber and the single-mode lithium niobate waveguide leads to low coupling efficiencies. Here, we demonstrate, both numerically and experimentally, that the problem can be solved with a tapered single mode fiber of an optimized mode field profile. Numerical simulation shows that the minimum coupling losses for the TE and TM mode are 0.32 dB and 0.86 dB, respectively. Experimentally, though without anti-reflection coating, the measured coupling losses for TE and TM mode are 1.32 dB and 1.88 dB, respectively. Our technique paves a way for a broad range of on-chip lithium niobate applications.

Fabrication of a multifunctional photonic integrated chip on lithium niobate on insulator using femtosecond laser-assisted chemomechanical polish.

We report fabrication of a multifunctional photonic integrated chip on lithium niobate on insulator, which is achieved by femtosecond laser-assisted chemomechanical polish. We demonstrate a high-extinction-ratio beam splitter, a 1×6 optical switch, and a balanced 3×3 interferometer on the fabricated chip by reconfiguring the microelectrode array integrated with the multifunctional photonic circuit.

High-Precision Propagation-Loss Measurement of Single-Mode Optical Waveguides on Lithium Niobate on Insulator.

We demonstrate the fabrication of single-mode optical waveguides on lithium niobate on an insulator (LNOI) by optical patterning combined with chemomechanical polishing. The fabricated LNOI waveguides had a nearly symmetric mode profile of ~2.5 µm mode field size (full-width at half-maximum). We developed a high-precision measurement approach by which single-mode waveguides were characterized to have propagation loss of ~0.042 dB/cm.

Fabrication of Crystalline Microresonators of High Quality Factors with a Controllable Wedge Angle on Lithium Niobate on Insulator.

We report the fabrication of crystalline microresonators of high quality (Q) factors with a controllable wedge angle on lithium niobate on insulator (LNOI). Our technique relies on a femtosecond laser assisted chemo-mechanical polish, which allows us to achieve ultrahigh surface smoothness as critically demanded by high Q microresonator applications. We show that by refining the polish parameters, Q factors as high as 4.7 × 107 can be obtained and the wedge angle of the LNOI can be continuously tuned from 9° to 51°.

Real-time electrical tuning of an optical spring on a monolithically integrated ultrahigh Q lithium nibote microresonator.

Cavity optomechanics, the study of the interplay between light and mechanical properties of matter, has triggered a wide range of research from cavity quantum electrodynamics, label-free single molecule detection to the creation of phonon lasers. Using femtosecond laser direct writing followed by chemomechanical polishing, here we report an ultrahigh quality (Q∼107) factor lithium niobate whispering gallery microresonator monolithically integrated with inplane microelectrodes. Coherent regenerative optomechanical oscillation with an effective mechanical quality factor as high as 2.86×108 is observed in air. We demonstrate real-time electrical tuning of the optomechanical frequency with an electromechanical tuning efficiency around -134 kHz/100 V.

Efficient electro-optical tuning of an optical frequency microcomb on a monolithically integrated high-Q lithium niobate microdisk.

We demonstrate efficient tuning of a monolithically integrated lithium niobate (LN) microdisk optical frequency microcomb. Utilizing the high optical quality (Q) factor (i.e., Q∼7.1×106) of the microdisk, the microcomb spans over a spectral bandwidth of ∼200nm at a pump power as low as 20.4 mW. Combining the large electro-optic coefficient of LN and the optimum design of the geometry of microelectrodes, we demonstrate electro-optical tuning of the comb with a spectral range of 400 pm and a tuning efficiency of ∼38pm/100V.

Long Low-Loss-Litium Niobate on Insulator Waveguides with Sub-Nanometer Surface Roughness.

In this paper, we develop a technique for realizing multi-centimeter-long lithium niobate on insulator (LNOI) waveguides with a propagation loss as low as 0.027 dB/cm. Our technique relies on patterning a chromium thin film coated on the top surface of LNOI into a hard mask with a femtosecond laser followed by chemo-mechanical polishing for structuring the LNOI into the waveguides. The surface roughness on the waveguides was determined with an atomic force microscope to be 0.452 nm. The approach is compatible with other surface patterning technologies, such as optical and electron beam lithographies or laser direct writing, enabling high-throughput manufacturing of large-scale LNOI-based photonic integrated circuits.

Sucrose metabolism gene families and their biological functions.

Sucrose, as the main product of photosynthesis, plays crucial roles in plant development. Although studies on general metabolism pathway were well documented, less information is available on the genome-wide identification of these genes, their expansion and evolutionary history as well as their biological functions. We focused on four sucrose metabolism related gene families including sucrose synthase, sucrose phosphate synthase, sucrose phosphate phosphatase and UDP-glucose pyrophosphorylase. These gene families exhibited different expansion and evolutionary history as their host genomes experienced differentiated rates of the whole genome duplication, tandem and segmental duplication, or mobile element mediated gene gain and loss. They were evolutionarily conserved under purifying selection among species and expression divergence played important roles for gene survival after expansion. However, we have detected recent positive selection during intra-species divergence. Overexpression of 15 sorghum genes in Arabidopsis revealed their roles in biomass accumulation, flowering time control, seed germination and response to high salinity and sugar stresses. Our studies uncovered the molecular mechanisms of gene expansion and evolution and also provided new insight into the role of positive selection in intra-species divergence. Overexpression data revealed novel biological functions of these genes in flowering time control and seed germination under normal and stress conditions.

Aged monkey brains reveal the role of ubiquitin-conjugating enzyme UBE2N in the synaptosomal accumulation of mutant huntingtin.

Although misfolded proteins are ubiquitinated and cleared by the proteasome, they can accumulate in synapses in aged neurons to promote synaptic dysfunction in a variety of neurodegenerative diseases, including Huntington's disease (HD), which is caused by polyglutamine expansion in huntingtin. The mechanism behind this aging-related phenomenon is unknown and has been difficult to investigate using animals with short life spans. With brain tissues from longer-lived rhesus monkeys of different ages, we found that aging reduces ubiquitin-proteasomal activity and also increases the level of ubiquitin-conjugating enzyme UBE2N (Ubc13) in synaptosomes. Synaptosomal fractions from aged monkey brain increase in vitro ubiquitinated huntingtin, whereas depletion of UBE2N markedly reduces this increase. Overexpressing UBE2N increases the aggregation of mutant huntingtin, and reducing UBE2N attenuates huntingtin aggregation in cellular and mouse models of HD. Our studies suggest that increased UBE2N plays a critical role in the synaptosomal accumulation of mutant huntingtin with age.

Genome-wide expansion and expression divergence of the basic leucine zipper transcription factors in higher plants with an emphasis on sorghum.

Plant bZIP transcription factors play crucial roles in multiple biological processes. However, little is known about the sorghum bZIP gene family although the sorghum genome has been completely sequenced. In this study, we have carried out a genome-wide identification and characterization of this gene family in sorghum. Our data show that the genome encodes at least 92 bZIP transcription factors. These bZIP genes have been expanded mainly by segmental duplication. Such an expansion mechanism has also been observed in rice, arabidopsis and many other plant organisms, suggesting a common expansion mode of this gene family in plants. Further investigation shows that most of the bZIP members have been present in the most recent common ancestor of sorghum and rice and the major expansion would occur before the sorghum-rice split era. Although these bZIP genes have been duplicated with a long history, they exhibited limited functional divergence as shown by nonsynonymous substitutions (Ka)/synonymous substitutions (Ks) analyses. Their retention was mainly due to the high percentages of expression divergence. Our data also showed that this gene family might play a role in multiple developmental stages and tissues and might be regarded as important regulators of various abiotic stresses and sugar signaling.

Characterization of a sodium-regulated glutaminase from cyanobacterium Synechocystis sp. PCC 6803.

Glutaminase is widely distributed among microorganisms and mammals with important functions. Little is known regarding the biochemical properties and functions of the deamidating enzyme glutaminase in cyanobacteria. In this study a putative glutaminase encoded by gene slr2079 in Synechocystis sp. PCC 6803 was investigated. The slr2079 was expressed as histidine-tagged fusion protein in Escherichia coli. The purified protein possessed glutaminase activity, validating the functional assignment of the genomic annotation. The apparent K (m) value of the recombinant protein for glutamine was 26.6 +/- 0.9 mmol/L, which was comparable to that for some of other microbial glutaminases. Analysis of the purified protein revealed a two-fold increase in catalytic activity in the presence of 1 mol/L Na(+). Moreover, the K (m) value was decreased to 12.2 +/- 1.9 mmol/L in the presence of Na(+). These data demonstrate that the recombinant protein Slr2079 is a glutaminase which is regulated by Na(+) through increasing its affinity for substrate glutamine. The slr2079 gene was successfully disrupted in Synechocystis by targeted mutagenesis and the Deltaslr2079 mutant strain was analyzed. No differences in cell growth and oxygen evolution rate were observed between Deltaslr2079 and the wild type under standard growth conditions, demonstrating slr2079 is not essential in Synechocystis. Under high salt stress condition, however, Deltaslr2079 cells grew 1.25-fold faster than wild-type cells. Moreover, the photosynthetic oxygen evolution rate of Deltaslr2079 cells was higher than that of the wild-type. To further characterize this phenotype, a number of salt stress-related genes were analyzed by semi-quantitative RT-PCR. Expression of gdhB and prc was enhanced and expression of desD and guaA was repressed in Deltaslr2079 compared to the wild type. In addition, expression of two key enzymes of ammonium assimilation in cyanobacteria, glutamine synthetase (GS) and glutamate synthase (GOGAT) was examined by semi-quantitative RT-PCR. Expression of GOGAT was enhanced in Deltaslr2079 compared to the wild type while GS expression was unchanged. The results indicate that slr2079 functions in the salt stress response by regulating the expression of salt stress related genes and might not play a major role in glutamine breakdown in Synechocystis.