Synthesis of N-H Aziridines from Unactivated Olefins Using Hydroxylamine-O-Sulfonic Acids as Aminating Agent.

Herein, we presented a practical methodology for the intermolecular aziridination of alkenes, using HOSA as the aminating agent, alongside pyridine or piperidine as the base, within HFIP solvent system. Notably, this approach showcases excellent reactivity, especially with nonactivated alkenes, and facilitates the transformation of various alkenes substrates, including mono-, di-, tri, and tetra-substituted alkenes, into aziridines with moderate to excellent yield. This method presents a promising avenue for synthesizing aziridines from a wide range of alkenes, featuring the benefits of straightforward operation, mild reaction conditions, extensive substrate compatibility, and scalability.

Sulfonated Polyimide Membranes Constructed by Main-Chain and Molecular-Network Engineering Strategy for Direct Methanol Fuel Cell.

Excessive swelling is one important factor that leads to high fuel permeability and limited operating concentration of methanol for proton exchange membranes. Herein, a collaborative strategy of main-chain and molecular-network engineering is applied to lower swelling ratio and improve methanol resistance for highly sulfonated polyimide. Two m-phenylenediamine monomers (4-(2,3,5,6-tetrafluoro-4-vinylphenoxy)benzene-1,3-diamine and 4,6-bis(2,3,5,6-tetrafluoro-4-vinylphenoxy)benzene-1,3-diamine) with tetrafluorostyrol groups are designed and synthesized. Two series of cross-linked sulfonated polyimides (CSPI-Ts, CSPI-Bs) are prepared from the two diamines, 4,4'-diaminostilbene-2,2'-disulfonic acid and 1,4,5,8-naphthalenetetracarboxylicdianhydride. The rigid main-chain structure is cornerstone for wet CSPI-Ts and CSPI-Bs remaining stable at elevated temperatures. The introduction of hydrophobic cross-linked network further improves their dimensional stability and methanol resistance. CSPI-Ts and CSPI-Bs show obviously improved performances containing high proton conductivity (121 ± 0.27-158 ± 0.35 S cm-1 ), low swelling ratio (9.6 ± 0.40%-16.1 ± 0.01%) and methanol permeability (4.14-7.69 × 10-7 cm2 s-1 ) at 80 °C. The direct methanol fuel cell (DMFC) is assembled from CSPI-T-10 with balanced properties, and it exhibits high maximum power density (PDmax ) of 82.3 and 72.6 mW cm-2 in 2 and 10 m methanol solution, respectively. The ratio of PDmax in 10 m methanol solution to the value in 2 m methanol solution is as high as 88%. The CSPI-T-10 is promising proton exchange membrane candidate for DMFC application.

Ligand-Promoted Iron-Catalyzed Nitrene Transfer for the Synthesis of Hydrazines and Triazanes through N-Amidation of Arylamines.

Herein, we report that bulky alkylphosphines such as PtBu3 can switch the roles from actor to spectator ligands to promote the FeCl2 -catalyzed N-amidation reaction of arylamines with dioxazolones, giving hydrazides in high efficiency and chemoselectivity. Mechanistic studies indicated that the phosphine ligands could facilitate the decarboxylation of dioxazolones on the Fe center, and the hydrogen bonding interactions between the arylamines and the ligands on Fe nitrenoid intermediates might play a role in modulating the delicate interplay between the phosphine ligand, arylamine, and acyl nitrene N, favoring N-N coupling over N-P coupling. The new ligand-promoted N-amidation protocols offer a convenient way to access various challenging triazane compounds via double or sequential N-amidation of primary arylamines.

Metagenomics study on taxonomic and functional change of gut microbiota in patients with obesity with PCOS treated with exenatide combination with metformin or metformin alone.

OBJECTIVE: To investigate the effect of exenatide treatment on the composition of intestinal flora and metabolic pathways in patients with obesity with polycystic ovary syndrome. METHODS: Patients with obesity with polycystic ovary syndrome (PCOS) were distributed to two groups: one received exenatide combined with metformin (COM group, n = 14) and the other used metformin alone (MF group, n = 15). Fresh fecal specimens from the participants, including 29 patients with obesity with PCOS and 6 healthy controls, were collected for metagenomic sequencing. The effect of exenatide combination with metformin or metformin alone on the composition and function of intestinal flora in patients with obesity with PCOS were compared by bioinformatics analysis. RESULTS: The level of BMI, TT, HbA1c, and HDL-c was significantly improved in both groups. The MF and COM groups were abundant in Firmicutes, Bacteroidetes, Uroviricota, Actinobacteria, and Proteobacteria. Abundance of Bacteroidetes, Proteobacteria, Hungatella, and certain probiotics like Phocaeicola and Anaerobutyricum significantly increased in both groups after treatment. Enriched microbial species in the MF and COM group were different. Clostridium, Fusobacterium, and Oxalobacter were the main bacteria in the post-MF group, while Lactococcus_garvieae, Clostridium_perfringens, and Coprococcus_sp_AF16_5 were the main bacteria in the post-COM group. The post-COM group had more probiotic species including Bifidobacterium, Prevotella, and Anaerobutyricum after treatment. CONCLUSION: Both exenatide combined with metformin and metformin monotherapy can improve metabolic and endocrine markers, and the diversity and abundance of gut microbiota in patients with obesity with PCOS. The effects of the combination and monotherapy agents on intestinal flora were consistent to some extent but also unique respectively.

Clinical presentation of perineal endometriosis and prognostic nomogram after surgical resection.

BACKGROUND: This retrospective study evaluated the clinical features of perineal endometriosis (PEM) and established a prognostic nomogram for recurrence probability in patients treated with surgical resection. METHODS: This study enrolled 130 PEM patients who had received surgical treatment in Peking Union Medical College Hospital (PUMCH) between January 1992 and September 2020. We collected their clinical features and conducted outpatient or telephone follow-up. The predictive nomogram was constructed based on 104 patients who had completed follow-up by July 2021. The Cox proportional hazards regression model was used to evaluate the prognostic effects of multiple clinical parameters on recurrence. The Index of concordance (C-index) and calibration curves were used to access the discrimination ability and predictive accuracy of the nomogram respectively, and the results were further validated via bootstrap resampling. Calculating the area under the curve (AUC) via risk scores of patients aimed to further access the predictive power of the model. In addition, the survival curve was depicted using Kaplan-Meier plot and compared by log-rank method. RESULTS: Most PEM patients had been symptomatic for 24-48 months before the lesion resection. With a median 99.00 (interquartile range: 47.25-137.50) months of postoperative observation, there were 16 (15.1%) out of 104 cases who finished follow-up reported symptomatic recurrence. On multivariate analysis of derivation cohort, multiple lesions, microscopically positive margin (mPM) and anal sphincter involvement (ASI) were selected into the nomogram. The C-index of the nomogram for predicting recurrence was 0.84 (95% CI 0.77-0.91). The calibration curve for probability of recurrence for 36, 60 and 120 months showed great agreement between prediction by nomogram and actual observation. Furthermore, the AUCs of risk score for 36, 60 and 120 months were 0.89, 0.87 and 0.82 respectively. CONCLUSIONS: PEM is a rare kind of endometriosis and surgery is the primary treatment. Multiple lesions and ASI are independent risk factors for postoperative recurrence, and wide resection with more peripheral tissue could be preferred. The proposed nomogram resulted in effective prognostic prediction for PEM patients receiving surgical excision. In addition, this predictive nomogram needs external data sets to further validate its prognostic accuracy in the future.

Comparative evaluation of low-level light therapy and ethinyl estradiol and desogestrel combined oral contraceptive for clinical efficacy and regulation of serum biochemical parameters in primary dysmenorrhoea: a prospective randomised multicentre trial.

We aimed to compare low-level light therapy with oral contraceptive pills for pain relief and serum levels of nitric oxide and prostaglandin E2 in patients with primary dysmenorrhoea. This was a randomised, active comparator-controlled, multicentre study. In total, 156 patients were randomised to receive either low-level light therapy with light-emitting diodes (LED) applying on two acupoints, namely, conception vessel 4 (CV4) and CV6 or conventional treatment with oral Marvelon, 30 µg of ethinyl estradiol and 150 µg of desogestrel (DSG/EE), for three consecutive menstrual cycles. The main outcome was the proportion of patients who achieved 33% or more decrease in pain scores measured using the visual analogue scale, which was deemed as efficient rate. Absolute changes in visual analogue scale scores, serum levels of nitric oxide (assessed by nitrites and nitrates reflecting nitric oxide metabolism) and prostaglandin E2 (measured by enzyme-linked immunosorbent assay) were the secondary outcomes. A total of 135 patients completed the study (73 in the light therapy group and 62 in the DSG/EE group). The efficient rate at the end of treatment was comparable between the groups (73.6% vs. 85.7%, χ2 = 2.994, p = 0.084). A more significant reduction in pain scores was observed in the DSG/EE group (39.25% vs. 59.52%, p < 0.001). Serum levels of prostaglandin E2 significantly decreased from baseline but did not differ between groups (- 109.57 ± 3.99 pg/mL vs. - 118.11 ± 12.93 pg/mL, p = 0.51). Nitric oxide concentration remained stable in both groups. Low-level light therapy with LED-based device applied on acupuncture points CV4 and CV6 demonstrated a similar level of dysmenorrhoea pain reduction to DSG/EE combined contraceptive. Both treatment modalities achieved clinically meaningful levels of pain reduction. Registration on ClinicalTrials.gov: TRN: NCT03953716, Date: April 04, 2019.

Dual-epitaxy Si/Ge broadband photodetector for application in cryogenic radiometer.

A dual-epitaxy Si/Ge broadband photodetector covering the wavelength range from 400 nm to 1600 nm was developed and demonstrated. The detector was realized on silicon platform with vertically stacked epitaxial Si and Ge layers in the detector's depletion region, which combined the response from a Si detector and a Ge detector. Under room temperature, dark current density of dual-epitaxy Si/Ge broadband photodetector is 1.3E-4 A/mm2 at 2 V reverse bias. The dual-epitaxy Si/Ge broadband has its peak spectral responsivity response of more than 0.6 A/W near 1000 nm wavelength and has spectral responsivity above 0.1A/W in the range from 450 nm to 1600 nm. Its temperature dependency was studied. The dual-epitaxy Si/Ge quadrant detector was proved working in the application of absolution optical power measurement in cryogenic radiometer.

Preventive therapeutic options for postoperative recurrence of ovarian endometrioma: gonadotropin-releasing hormone agonist with or without levonorgestrel intrauterine system insertion.

PURPOSE: Here, we compared endometrioma recurrence rates in patients who have undergone a laparoscopic cystectomy and treated with a gonadotropin-releasing hormone agonist (GnRHa) alone or a GnRHa combined with a levonogestrel intrauterine system (LND-IUS). METHODS: We enrolled endometrioma patients who underwent laparoscopic cyst enucleation and divided them into two groups according to postoperative management: GnRHa alone and GnRHa in combination with LND-IUS. We compared preoperative history, perioperative parameters, postoperative endometrioma recurrence, and symptoms between these two groups. RESULTS: A total of 320 patients were included in the final analysis. With a median 84.6 months of follow-up, we detected significant differences between the two groups with respect to age at surgery (31.6 ± 4.8 vs. 37.6 ± 4.2 years, χ2 = 1.978, p < 0.001), gravida (0 vs. 2, χ2 = 4.391, p < 0.001), parity (0 vs. 1, χ2 = 0.035, p < 0.001), body mass index (21.0 ± 2.5 vs. 21.9 ± 2.4, χ2 = 0.0096, p = 0.009), r-AFS score (48 vs. 64, χ2 = 4.888, p = 0.001), and operation time (60 vs. 75 min, χ2 = 9.119, p = 0.003). Patients treated with both GnRHa and LND-IUS achieved significantly less endometrioma recurrence (23.6 vs. 11.5%, χ2 = 5.202, p = 0.023) and higher rates of pain remission (92.1 vs. 100%, χ2 = 6.511, p = 0.011), while those with GnRHa alone suffered more recurrent and painful symptoms (χ2 = 9.280, p = 0.026). Multivariate analysis using a Cox regression demonstrated that combined GnRHa and LNG-IUS treatment correlated with a decreased endometrioma recurrence rate after laparoscopic cystectomy (RR 0.369, 95% CI 0.182-0.749, p = 0.006). CONCLUSIONS: Combination treatment of GnRHa and LNG-IUS exhibited superior pain relief and recurrence prevention among endometrioma patients after fertility-sparing surgery. Thus, combination treatment is a preferable long-term option for patients without intent for pregnancy in the near future.

CMOS-compatible all-Si metasurface polarizing bandpass filters on 12-inch wafers.

The implementation of polarization controlling components enables additional functionalities of short-wave infrared (SWIR) imagers. The high-performance and mass-producible polarization controller based on Si metasurface is in high demand for the next-generation SWIR imaging system. In this work, we report the first demonstration of all-Si metasurface based polarizing bandpass filters (PBFs) on 12-inch wafers. The PBF achieves a polarization extinction ratio of above 10 dB in power within the passbands. Using the complementary metal-oxide-semiconductor (CMOS) compatible 193nm ArF deep ultra-violet (DUV) immersion lithography and inductively coupled plasma (ICP) etch processing line, a device yield of 82% is achieved.

Thermal annealing study of the mid-infrared aluminum nitride on insulator (AlNOI) photonics platform.

Aluminum nitride on insulator (AlNOI) photonics platform has great potential for mid-infrared applications thanks to the large transparency window, piezoelectric property, and second-order nonlinearity of AlN. However, the deployment of AlNOI platform might be hindered by the high propagation loss. We perform thermal annealing study and demonstrate significant loss improvement in the mid-infrared AlNOI photonics platform. After thermal annealing at 400°C for 2 hours in ambient gas environment, the propagation loss is reduced by half. Bend loss and taper coupling loss are also investigated. The performance of multimode interferometer, directional coupler, and add/drop filter are improved in terms of insertion loss, quality factor, and extinction ratio. Fourier-transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction spectroscopy suggest the loss improvement is mainly attributed to the reduction of extinction coefficient in the silicon dioxide cladding. Apart from loss improvement, appropriate thermal annealing also helps in reducing thin film stress.

Aluminum nitride on insulator (AlNOI) platform for mid-infrared photonics.

We report an aluminum nitride on insulator platform for mid-infrared (MIR) photonics applications beyond 3 µm. Propagation loss and bending loss are studied, while functional devices such as directional couplers, multimode interferometers, and add/drop filters are demonstrated with high performance. The complementary metal-oxide-semiconductor-compatible aluminum nitride offers advantages ranging from a large transparency window, high thermal and chemical resistance, to piezoelectric tunability and three-dimensional integration capability. This platform can have synergy with other photonics platforms to enable novel applications for sensing and thermal imaging in MIR.

Effect of Menopausal Hormone Therapy on Bone Mineral Density in Chinese Women: A 2-Year, Prospective, Open-Label, Randomized-Controlled Trial.

BACKGROUND This study was designed to explore the effect of menopausal hormone therapy (MHT) on bone mineral density (BMD) in Chinese women. MATERIAL AND METHODS This was a prospective, open-label, randomized-controlled clinical trial. We randomly assigned 123 postmenopausal women to 3 groups: group A received 0.625 mg conjugated equine estrogen (CEE) plus 100 mg micronized progesterone (MP), group B received 0.3 mg CEE daily plus 100 mg MP, and group C received 0.625 mg CEE daily plus 10 mg dydrogesterone (DHG). All subjects received a 2-year intervention and drugs were given in a continuous sequential pattern. RESULTS Ninety-six patients were followed up. At 1 year, groups A and B gained 2.31% and 1.95% BMD, respectively (P<0.01); at 2 years, groups B and C gained 2.37% and 4.15% BMD (P<0.01) respectively. At 2 years, group A gained 3.28% BMD in the femoral neck and 3.77% BMD in Ward's triangle (P<0.05). At 1 year, group B lost 2.14% BMD in the trochanter and 1.20% BMD in the total hip (P<0.05); at 2 years, group B lost 1.51% BMD in the total hip (P<0.01). ALP, Ca, P, and Ca/Cr levels were all decreased in the 3 groups (P<0.05). The changes in Cr level at 1 and 2 years were not significant when compared with baseline in all groups (P>0.05). CONCLUSIONS Both lower-dose and standard-dose CEE increased lumbar BMD, sustain femoral neck BMD, and Ward's triangle BMD, while there was a reduced bone turnover rate. Standard-dose CEE combined with MP can increase BMD at these 2 sites. CEE combined with MP is recommended because it has better clinical benefits.

Bone protection for early menopausal women in China: standard or half-dose estrogen with progestin? A one-year prospective randomized trail.

The aim of the study is to compare the bone sparing effect of half-dose with standard-dose conjugated equine estrogen (CEE) combined with progestin. A total of 123 participants were administrated with 0.625 mg of CEE and 100 mg of micronized progesterone (MP) in group A, 0.3 mg of CEE and 100 mg of MP in group B, 0.625 mg of CEE and 10 mg of dydrogesterone (DDG) in group C for one year. Percent changes from baseline in BMD at lumbar spine and fracture rate were primary outcomes. Secondary endpoints included changes of BMD at femoral neck, total hip and arm, bone markers (alkaline phosphatase, calcium and phosphorus), serum alanine aminotransferase (ALT) and endometrial thickness. No fractures occurred during the treatment. Standard dose of CEE leads to significant changes in lumbar spine and arm. The 3.78% growth of BMD at femoral neck in group C marked a statistically difference. There was no statistically remarkable bone loss at hip in all three groups. Bone turnover markers and ALT significantly decreased from basic values. Endometrium thickened more with traditional dose of CEE. Both the half and standard dose CEE are effective in BMD preservation among early menopausal women with subtle side effects. Low-dose estrogen is less efficacious than traditional one.

Demonstration of color display metasurfaces via immersion lithography on a 12-inch silicon wafer.

The demonstration of a color display metasurface on a 12-inch silicon wafer with critical dimension (CD) below 100 nm by complementary metal-oxide semiconductor (CMOS) compatible technology is reported for the first time. The 193 nm ArF deep UV immersion lithography is leveraged instead of electron beam lithography (EBL) to pattern the metasurface, which greatly improves the efficiency while keeping a high resolution. The demonstrated metasurface successfully generates the resonant modes and reflects the lights at resonance wavelengths, giving its display in red, green, and blue (RGB) colors. The wafer-level uniformities of CD and reflection characteristic of the metasurface are measured and analyzed. The experimental data show that they are well controlled in the fabrication process. The work provides a promising route towards mass production of dielectric metasurfaces.

Aluminum nitride electro-optic phase shifter for backend integration on silicon.

An AlN electro-optic phase shifter with a parallel plate capacitor structure is fabricated on Si using the back-end complementary metal-oxide-semiconductor technology, which is feasible for multilayer photonics integration. The modulation efficiency (Vπ⋅Lπ product) measured from the fabricated waveguide-ring resonators and Mach-Zehnder Interferometer (MZI) modulators near the 1550-nm wavelength is ∼240 V⋅cm for the transverse electric (TE) mode and ∼320 V⋅cm for the transverse magnetic (TM) mode, from which the Pockels coefficient of the deposited AlN is deduced to be ∼1.0 pm/V for both TE and TM modes. The methods for further modulation efficiency improvement are addressed.

Guided mode resonance enabled ultra-compact Germanium photodetector for 1.55 µm detection.

We propose a novel technique of enhancing the photodetection capabilities of ultrathin Ge films for normally incident light at 1.55 µm through the guided mode resonance (GMR) phenomenon. Specifically, by suitably patterning the surface of a Ge thin film, it is possible to excite guided modes which are subsequently coupled to free space radiative modes, resulting in spectral resonances that possess locally enhanced near fields with a large spatial extent. Absorption is found to be enhanced by over an order of magnitude over a pristine Ge film of equal thickness. Furthermore, attenuation of incident light for such a structure occurs over very few grating periods, resulting in significantly enhanced theoretical 3 dB bandwidth-efficiency products of ~58 GHz. The nature of the enhancement mechanism also produces spectrally narrow resonances (FWHM ~30 nm) that are polarization sensitive and exhibit excellent angular tolerance. Finally, the proposed device architecture is fully compatible with existing Si infrastructure and current CMOS fabrication processes.

Design of an ultra-compact electro-absorption modulator comprised of a deposited TiN/HfO2/ITO/Cu stack for CMOS backend integration.

An ultra-compact electro-absorption (EA) modulator operating around 1.55-µm telecom wavelengths is proposed and theoretically investigated. The modulator is comprised of a stack of TiN/HfO2

Phase modulation in horizontal metal-insulator-silicon-insulator-metal plasmonic waveguides.

An extremely compact Si phase modulator is proposed and validated, which relies on effective modulation of the real part of modal index of horizontal metal-insulator-Si-insulator-metal plasmonic waveguides by a voltage applied between the metal cover and the Si core. Proof-of-concept devices are fabricated on silicon-on-insulator substrates using standard complementary metal-oxide-semiconductor technology using copper as the metal and thermal silicon dioxide as the insulator. A modulator with a 1-µm-long phase shifter inserted in an asymmetric Si Mach-Zehnder interferometer exhibits 9-dB extinction ratio under a 6-V/10-kHz voltage swing. Numerical simulations suggest that high speed and low driving voltage could be achieved by shortening the distance between the Si core and the n(+)-contact and by using a high-κ dielectric as the insulator, respectively.

Silicon nitride based plasmonic components for CMOS back-end-of-line integration.

Silicon nitride waveguides provide low propagation loss but weak mode confinement due to the relatively small refractive index contrast between the Si3N4 core and the SiO2 cladding. On the other hand, metal-insulator-metal (MIM) plasmonic waveguides offer strong mode confinement but large propagation loss. In this work, MIM-like plasmonic waveguides and passive devices based on horizontal Cu-Si3N4-Cu or Cu-SiO2-Si3N4-SiO2-Cu structures are integrated in the conventional Si3N4 waveguide circuits using standard CMOS backend processes, and are characterized around 1550-nm telecom wavelengths using the conventional fiber-waveguide-fiber method. The Cu-Si3N4(~100 nm)-Cu devices exhibit ~0.78-dB/µm propagation loss for straight waveguides, ~38% coupling efficiency with the conventional 1-µm-wide Si3N4 waveguide through a 2-µm-long taper coupler, ~0.2-dB bending loss for sharp 90° bends, and ~0.1-dB excess loss for ultracompact 1 × 2 and 1 × 4 power splitters. Inserting a ~10-nm SiO2 layer between the Si3N4 core and the Cu cover (i.e., the Cu-SiO2(~10 nm)-Si3N4(~100 nm)-SiO2(~10 nm)-Cu devices), the propagation loss and the coupling efficiency are improved to ~0.37 dB/µm and ~52% while the bending loss and the excess loss are degraded to ~3.2 dB and ~2.1 dB, respectively. These experimental results are roughly consistent with the numerical simulation results after taking the influence of possible imperfect fabrication into account. Ultracompact plasmonic ring resonators with 1-µm radius are demonstrated with an extinction ratio of ~18 dB and a quality factor of ~84, close to the theoretical prediction.