Transmission properties of grating-gate GaN-based HEMTs under different incident angles in the mid-infrared region.

The absorption tunability of grating-gate GaN-based HEMTs in the mid-infrared region has been confirmed in wide frequency regions. However, the application potential of grating-gate GaN-based HEMTs is limited due to a lack of study on transmission properties under different incident angles. Therefore, this paper studied the transmission characteristics of grating-gate GaN-based HEMTs under different incident angles in the mid-infrared region. By using the optical transfer matrix approach to model the dispersion characteristics in the structure, we found that the stronger plasmon polaritons and phonon polaritons occur in conductive channel and GaN layer. The variation of different incident wave vectors with incident angle affects the plasmon polaritons and phonon polaritons excitation intensities, resulting in the angular tunability transmission properties of grating-gate GaN-based HEMTs. After simulating the electric field distribution in COMSOL, the different transmission properties of grating-gate GaN-based HEMTs occur under different incident angles. Simulated results reveal the excellent angle-selectivity in grating-gate GaN-based HEMTs. The research into these characteristics shows that the structure has a lot of promise for designing mid-infrared angle selection filters, sensors, and other subwavelength devices in the future.

Polarization properties in grating-gated AlN/GaN HEMTs at mid-infrared frequencies.

The plasmon resonances of grating-gated AlN/GaN HEMTs can occur in wide frequency regions at mid-infrared frequencies. However, the lack of polarization properties research in grating-gated AlN/GaN HEMTs prevents the application potential. In order to solve the problem, the polarization properties in grating-gated AlN/GaN HEMTs at mid-infrared frequencies were studied in the paper. After using the optical transfer matrix method to calculate the dispersion curves in grating-gated AlN/GaN HEMTs, the plasmon polaritons in conductive channel and phonon polaritons in GaN layer occur under TM incident waves rather than TE incident waves. The phenomenon illustrates the potential of polarization-selectivity has existed in grating-gated AlN/GaN HEMTs. To study the polarization properties of grating-gated AlN/GaN HEMTs in detail, the electric field distribution and transmission properties of the structure were simulated in COMSOL. The results show the excellent polarization-selectivity at mid-infrared frequencies in grating-gated AlN/GaN HEMTs. The studies of these characteristics indicate the vast potential for using grating-gated AlN/GaN HEMTs to design mid-infrared polarizers, mid-infrared polarization state modulators and other devices in the future.

Graphene Electro-Optical Switch Modulator by Adjusting Propagation Length Based on Hybrid Plasmonic Waveguide in Infrared Band.

A modulator is the core of many optoelectronic applications such as communication and sensing. However, a traditional modulator can hardly reach high modulation depth. In order to achieve the higher modulation depth, a graphene electro-optical switch modulator is proposed by adjusting propagation length in the near infrared band. The switch modulator is designed based on a hybrid plasmonic waveguide structure, which is comprised of an SiO2 substrate, graphene-Si-graphene heterostructure, Ag nanowire and SiO2 cladding. The propagation length of the hybrid plasmonic waveguide varies from 0.14 µm to 20.43 µm by the voltage tunability of graphene in 1550 nm incident light. A modulator with a length of 3 µm is designed based on the hybrid waveguide and it achieves about 100% modulation depth. The lower energy loss (~1.71 fJ/bit) and larger 3 dB bandwidth (~83.91 GHz) are attractive for its application in a photoelectric integration field. In addition, the excellent robustness (error of modulation effects lower than 8.84%) is practical in the fabrication process. Most importantly, by using the method of adjusting propagation length, other types of graphene modulators can also achieve about 100% modulation depth.

A New Electro-Optical Switch Modulator Based on the Surface Plasmon Polaritons of Graphene in Mid-Infrared Band.

In this paper, a new electro-optical switch modulator based on the surface plasmon polaritons of graphene is proposed. An air⁻graphene-substrate⁻dielectric structure is adopted in the modulator. In this structure, the graphene is considered as a film of metal whose thickness tends to be infinitesimal. By changing the external voltage, the boundary conditions can be changed to decide whether the surface plasmon polariton waves can be excited in mid-infrared band. Because of this effect, the structure can be used as an electro⁻optical switch modulator, whose modulation depth is about 100% in theory. Finally, the 3 dB bandwidth (~34 GHz) and the energy loss (36.47 fJ/bit) of the electro⁻optical switch modulator are given, whose low energy loss is very suitable for engineering applications.

[Epidemiological Characteristics of Lung Cancer Incidence 
in the Tumor Registration Area of Gansu Province from 2010 to 2019].

BACKGROUND: Lung cancer is the malignant tumor with the highest incidence rate and the heaviest disease burden in China. In recent years, lung cancer has shown a high incidence trend, seriously affecting the health of the population. In this paper, we analyze the characteristics of lung cancer incidence in 2019 and the trend of incidence rate from 2010-2019 in the tumor registration area of Gansu province, in order to provide a reference basis for the development of lung cancer prevention and control strategies in Gansu province. METHODS: By analyzing the cases of lung cancer incidence in the tumor registration area of Gansu province in 2019, we calculated the incidence rate, medium incidence rate, world incidence rate and other related indexes; we used Joinpoint to calculate the annual percentage change (APC) for trend analysis. RESULTS: In 2019, a total of 3757 new cases of lung cancer were reported in Gansu province, accounting for 14.96% of all new malignant tumors. The incidence rate, medium incidence rate and world incidence rate and world rate of lung cancer were 40.52/105, 25.78/105, 25.86/105; and the cumulative rate of 0-74 years old, and the truncation rate of 35-64 years old were 3.23%, 40.03/105, respectively. The incidence of lung cancer rises with age, and is high in the age group of 40 years and above, and the incidence peaks in the male and female populations in the group of 75 years and above, and the group of 80 years and above, respectively. The crude incidence rate of lung cancer in the tumor registration area of Gansu province from 2010-2019 showed an overall increasing trend, and the rate of increase was relatively fast, with an APC 5.39% (P<0.05); Separately, according to gender, urban and rural areas, the incidence of lung cancer in all populations showed an increasing trend, and the APC of male, female, urban and rural populations were 4.98%, 6.39%, 6.26%, and 4.64%, respectively (all P<0.05). According to the trend analysis of lung cancer incidence rate by age group, only lung cancer incidence in the age group of 65 years and above increased at an annual average rate of 4.15% (P<0.05). CONCLUSIONS: The incidence rate of lung cancer in the tumor registration area of Gansu province from 2010 to 2019 shows a rising trend year by year, and there are differences in the incidence of lung cancer in people of different genders, regions and age groups, so comprehensive prevention and control work should be carried out for the key populations of lung cancer incidence.

Dual Coupled Long-Range Hybrid Surface Plasmon Polariton Waveguide for Sub-Wavelength Confinement.

In this paper, a long-range hybrid waveguide for subwavelength confinement based on double SPP coupling is proposed. The hybrid waveguide consists of a metal-based cylindrical hybrid waveguide and a silver nanowire. There are two coupling regions in the waveguide structure that enhance mode coupling. Strong mode coupling enables the waveguide to exhibit both a small effective mode area (0.01) and an extremely long transmission length (700 µm). The figure of merit (FOM) of the waveguide can be as high as 4000. In addition, the cross-sectional area of the waveguide is only 500 nm × 500 nm, allowing optical operation in the subwavelength range, which helps enhance the miniaturization of optoelectronic devices. The excellent characteristics of the hybrid waveguide make it have potential applications in photoelectric integrated systems.

Spontaneous rupture of the urinary bladder: A rare case report.

Spontaneous rupture of the bladder (SRUB) is an extremely rare emergency that can be misdiagnosed due to its non-specific clinical presentation, leading to patient death. This study aimed to summarize SRUB's clinical features, diagnosis, and treatment through our case. We report a case of a 39-year-old female with preoperative peritonitis and peritoneal effusion diagnosis. We performed an emergency laparoscopic surgery and found she had a ruptured bladder. She was treated with laparoscopic rupture repair and suprapubic cystostomy. She recovered well, was discharged after seven days, and had the cystostomy tube removed after five weeks.

Hybrid Nanowire-Rectangular Plasmonic Waveguide for Subwavelength Confinement at 1550 Nm.

This paper presents a hybrid waveguide based on metal surface plasmon polaritons (SPPs) at 1550 nm comprising two silver (Ag) nanowires and a rectangular silicon (Si) waveguide. Due to the strong coupling effect observed in both the metal SPP mode and Si waveguide mode, excellent waveguide characteristics, such as a small effective modal area and long transmission length, could be achieved. The research results revealed that the proposed hybrid waveguide could achieve an ultra-long transmission distance of 270 µm and normalized effective mode area of 0.01. Furthermore, the cross-sectional size of the waveguide was 500 nm × 500 nm, which helped in achieving a subwavelength size. In addition, the hybrid waveguide was resistant to manufacturing errors. These excellent performances indicate that the proposed waveguide has great application potential in optoelectronic integrated circuits.

Association of CYP7A1 and CYP2E1 Polymorphisms with Type 2 Diabetes in the Chinese Han Populations.

Background: Type 2 diabetes mellitus (T2DM) is caused by diverse environmental and genetic risk factors. Previous studies have reported that cytochrome P450 (CYP) is a promising gene for T2DM. Therefore, we aimed to determine the effects of CYP7A1 and CYP2E1 polymorphisms on T2DM susceptibility among the Chinese Han population. Methods: A case-control study was conducted to assess the potential relationship of four polymorphisms (rs8192879, rs12542233, rs2070672 and rs2515641) with T2DM susceptibility in the Chinese population, involving 512 T2DM patients and 515 age- and gender-matched healthy individuals. We used the Agena MassARRAY platform to detect CYP7A1 and CYP2E1 polymorphisms. The relationship between genetic polymorphisms and T2DM risk was evaluated using odds ratios (ORs) and 95% confidence intervals (CIs) in various genetic models. Results: After adjusting for age and gender, rs12542233 in the CYP7A1 gene was significantly associated with decreased T2DM risk (recessive: OR = 0.67, 95% CI = 0.49-0.91, p = 0.012; after FDR correction, p = 0.048). The CYP7A1 rs12542233 was associated with a reduced risk of T2DM in people over 59 years of age (p = 0.010). In the population with BMI ≤ 24 kg/m2, CYP7A1 rs12542233 was associated with an increased risk of T2DM (p < 0.05). In the population with BMI > 24 kg/m2, CYP2E1 rs2515641 can significantly reduce the risk of T2DM (p < 0.05). And rs8192879, rs2070672 and rs2515641 could significantly increase the risk of diabetes retinopathy in T2DM patients (p < 0.05). Furthermore, the Trs8192879Crs12542233 haplotype was significantly associated with T2DM (p = 0.019). Conclusion: CYP7A1 and CYP2E1 polymorphisms may contribute to T2DM susceptibility in the Chinese Han population, especially in stratified analysis.

A case report of wandering spleen with pedicle torsion and splenic infarction being misdiagnosed as organ inversion complicated with acute appendicitis.

Wandering spleen is a rare disease that is easily misdiagnosed. When combined with splenic pedicle torsion and even splenic infarction, wandering spleen is a rare and critical cause of surgical acute abdomen. We report an 18-year-old male patient with abdominal organ inversion diagnosed as acute appendicitis before operation. Laparoscopic exploration confirmed wandering spleen with splenic pedicle torsion led to splenic infarction and was complicated by appendicitis. He was treated with laparoscopic appendectomy and abdominal splenectomy. The patient recovered well after the operation and was discharged from the hospital in 7 days. During the 4-year follow-up, there was no report of complicated infections such as pneumonia or sepsis.

Research Advances on Matrine.

Matrine is an alkaloid extracted from traditional Chinese herbs including Sophora flavescentis, Sophora alopecuroides, Sophora root, etc. It has the dual advantages of traditional Chinese herbs and chemotherapy drugs. It exhibits distinct benefits in preventing and improving chronic diseases such as cardiovascular disease and tumors. The review introduced recent research progresses on extraction, synthesis and derivatization of Matrine. The summary focused on the latest research advances of Matrine on anti-atherosclerosis, anti-hypertension, anti-ischemia reperfusion injury, anti-arrhythmia, anti-diabetic cardiovascular complications, anti-tumor, anti-inflammatory, anti-bacterium, anti-virus, which would provide new core structures and new insights for new drug development in related fields.

Research Advances on Anti-Cancer Natural Products.

Malignant tumors seriously threaten people's health and life worldwide. Natural products, with definite pharmacological effects and known chemical structures, present dual advantages of Chinese herbs and chemotherapeutic drug. Some of them exhibit favorable anti-cancer activity. Natural products were categorized into eight classes according to their chemical structures, including alkaloids, terpenoids and volatile oils, inorganic salts, phenylpropanoids, flavonoids and isoflavones, quinone, saponins and polysaccharides. The review focused on the latest advances in anti-cancer activity of representative natural products for every class. Additionally, anti-cancer molecular mechanism and derivatization of natural products were summarized in detail, which would provide new core structures and new insights for anti-cancer new drug development.

Filtering Characteristics of Phonon Polaritons Waves Based on Dielectric-h-BN-Dielectric Structure in Mid-Infrared Band.

Hyperbolic materials can be used to excite hyperbolic phonon polaritons in specific frequency bands, which causes abrupt interfaces with fluctuations of permittivity and different transmission characteristics at different incident wavelengths. Using the quasi-static approximation, the filtering characteristics of hexagonal Boron nitride (h-BN) and the transmission characteristics of phonon polaritons waves on a dielectric-h-BN-dielectric structure were studied in the paper. The results show that a smaller relative permittivity of the materials above and below h-BN and a thicker h-BN (ε1 = 1 (air), ε2 = 3.9 (SiO2), d = 100 nm) will lead to better filtering characteristics for different wavenumbers' incident waves (propagation length from 0.0028 µm to 1.9756 µm). Simulation results in COMSOL validated the previous theoretical calculations. Moreover, the transmissivity and 3dB bandwidth of the type-II band were calculated with different structure widths. The maximum transmissivity of ~99% appears at a width of 100 nm, and the minimum 3dB bandwidth reaches 86.35 cm-1 at a structure width of 1300 nm. When the structure width meets or exceeds 1700 nm, the 3dB bandwidth is equal to 0, and its structure length is the limit for the filter application. These characteristics reveal the excellent filtering characteristics of the dielectric-h-BN-dielectric structure, and reveal the great potential of using the dielectric-h-BN-dielectric structure to design optical filter devices with excellent performance in mid-infrared bands.

Electrical Phase Control Based on Graphene Surface Plasmon Polaritons in Mid-infrared.

Phase modulation of light is the core of many optoelectronic applications, such as electro-optic switch, sensors and modulators. Graphene Surface plasmon polaritons (SPPs) exhibit unique properties in phase modulation including dynamic tunability, a small driving voltage and small device size. In this paper, the novel phase modulation capability of graphene SPPs in mid-infrared are confirmed through theory and simulation. The results show that graphene SPPs can realize continuous tuning of the phase shift at multiple wavelengths in mid-infrared, covering the phase range from 0° to 360°. Based on these results, a sandwich waveguide structure of dielectric-graphene-dielectric with a device length of 800 nm is proposed, which shows up to 381° phase modulation range at an operating wavelength of 6.55 µm, given a 1 V driving voltage. In addition, the structure size is much shorter than the wavelength in mid-infrared and can realize sub-wavelength operation. This work paves the way to develop graphene-based tunable devices for mid-infrared wave-front control.

[Seed germination, bud growth and heavy-metal accumulation of Suaeda salsa].

Nickel and copper, as high toxic heavy metals (HMs), are the most serious contaminants in Jinchuan mining area, China. In this paper, the influence of combined HMs stress on the growth of widespread plant-S. salsa has been studied. The stress gradient of combined Ni-Cu was set based on the local environment and pre-experiment. Seed germination, growth, physiological characteristics of S. salsa were investigated by the control test, and its heavy metal bioaccumulation capacity was investigated by samples collected from field platform. The growth of S. salsa was promoted at lower concentration (≤40 mg/L) and inhibited at higher concentration (≥80 mg/L) under the single HMs stress and combined HMs stress (Cu20/Ni20). The malondialdehyde (MDA) content was increased with increasing concentration, and the soluble protein and free proline content in stress group were higher than that of in control group. Under single HMs stress, the peroxidase (POD) activity increased with increasing concentration; while under combined HMs stress, the POD activity increased initially and then reduced. Cu320 and Ni320 combined HMs stress inhibited the growth of S. salsa at all concentrations. The average translocation factors (TF) of S. salsa were greater than 1.00, and higher in leaves compared to stems. The results of bio-concentration factors (BCF) of S. salsa show that BCF of leaves were larger than that of roots and stems. At lower concentration, the combined HMs stress promoted the growth of S. salsa in comparison to single HMs stress, however, opposite results were obtained at higher concentration. Overall, S. salsa showed high tolerance to Cu and Ni and stronger capabilities of HMs uptake and translocation, and therefore, it can be used as an alternative plant for the bioremediation of heavy metal pollution in mining area.

An ELISA Assay for Quantifying Monomeric C-Reactive Protein in Plasma.

Native C-reactive protein (nCRP) is a non-specific marker of inflammation being claimed as a bystander in several chronic disorders. Accumulating evidence indicates that nCRP dissociates to and acts primarily as the monomeric conformation (mCRP) at inflammatory loci. This suggests that mCRP may be a superior disease marker with improved specificity and clear causality to the underlying pathogenesis. However, the lack of a feasible assay to quantify mCRP in clinical samples precludes the assessment of that suggestion. Here we report the development of a sandwich ELISA assay for quantification of plasma mCRP using commercially available reagents. Our assay is reproducible and highly conformation-specific showing a reliable detection limit of 1 ng/mL. We further show that mCRP appears to be a better marker than nCRP in several skin-related autoimmune disorders. This assay thus provides a useful tool to examine the clinical significance and utility of mCRP.

[Stat 3 signal transduction pathway correlates with proliferation of vascular smooth muscle cells of rats].

OBJECTIVE: To investigate the role of Stat3 (one of the signal transductant and activator) signal transduction pathway in proliferation of vascular smooth muscle cells (VSMCs). METHODS: VSMC was transfected with Stat3 antisense oligonucleotide. ELISA analysis was performed on Stat3 expression in cultured rat thoracic VSMC. Cell proliferation and toxicity assay by Methyl Thiazole (MTT) was used to measure the cell proliferation. The expression of Stat3, p-Stat3, Cyclin D1 and Bcl-x(L) were measured by Western blot. RESULTS: Stat3 protein expression was positive in VSMC. Targeting of Stat3 using antisense oligonucleotide directed against the translation site, resulted in significant growth inhibition and downregulation of Stat3, p-Stat3 and Cyclin D1. CONCLUSIONS: The increase of Stat3 correlates significantly with cell proliferation of VSMC. Cyclin D1 may be the critical target gene in mediating proliferation. Blocking Stat3 signal transduction pathway may inhibit the growth of VSMCs.