Identification of lipid synthesis genes in Schizochytrium sp. and their application in improving eicosapentaenoic acid synthesis in Yarrowia lipolytica.

BACKGROUND: Eicosapentaenoic acid (EPA) is widely used in the functional food and nutraceutical industries due to its important benefits to human health. Oleaginous microorganisms are considered a promising alternative resource for the production of EPA lipids. However, the storage of EPA in triglyceride (TG) becomes a key factor limiting its level. RESULTS: This study aimed to incorporate more EPA into TG storage through metabolic engineering. Firstly, key enzymes for TG synthesis, the diacylglycerol acyltransferase (DGAT) and glycerol-3-phosphate acyltransferase (GPAT) genes from Schizochytrium sp. HX-308 were expressed in Yarrowia lipolytica to enhance lipid and EPA accumulation. In addition, engineering the enzyme activity of DGATs through protein engineering was found to be effective in enhancing lipid synthesis by replacing the conserved motifs "HFS" in ScDGAT2A and "FFG" in ScDGAT2B with the motif "YFP". Notably, combined with lipidomic analysis, the expression of ScDGAT2C and GPAT2 enhanced the storage of EPA in TG. Finally, the accumulation of lipid and EPA was further promoted by identifying and continuing to introduce the ScACC, ScACS, ScPDC, and ScG6PD genes from Schizochytrium sp., and the lipid and EPA titer of the final engineered strain reached 2.25 ± 0.03 g/L and 266.44 ± 5.74 mg/L, respectively, which increased by 174.39% (0.82 ± 0.02 g/L) and 282.27% (69.70 ± 0.80 mg/L) compared to the initial strain, respectively. CONCLUSION: This study shows that the expression of lipid synthesis genes from Schizochytrium sp. in Y. lipolytica effectively improves the synthesis of lipids and EPA, which provided a promising target for EPA-enriched microbial oil production.

Magnetism and Optical Anisotropy in van der Waals Antiferromagnetic Insulator CrOCl.

van der Waals (vdW) magnetic insulators are of significance in both fundamental research and technological application, but most two-dimensional (2D) vdW magnetic systems are unstable and of high lattice symmetry. Stable 2D vdW magnetic insulators with anisotropic structure are needed to modulate the properties and unlock potential applications. Here we present a stable vdW antiferromagnetic material, CrOCl, with low-symmetry orthorhombic structure, and investigate systematically its magnetism, phase transition behavior, and optical anisotropy. Spin-phonon coupling effects are uncovered by the abnormal frequency shifts of Raman-active modes, suggesting the formation of a magnetic superstructure. The sizable abnormal change of interplanar spacing indicates the presence of a structural transition at around 27 K. Further in-plane vibrational, reflectional, and absorptional anisotropic properties are explored both experimentally and theoretically, revealing a highly polarization sensitive characteristic and linear dichroism in 2D CrOCl. Meanwhile, the particularly high polarization dependency of the second-harmonic generation and the nonlinear susceptibility of ∼2.24 × 10-11 m/V make it suitable in the field of polarization-dependent nonlinear optics. The findings on the intricate properties of 2D CrOCl lay foundations for future applications of low-symmetry vdW magnets in spin-dependent electronic and optoelectronic devices.

Comparison of clinical outcomes of expansive open-door laminoplasty with unilateral or bilateral fixation and fusion for treating cervical spondylotic myelopathy: a multi-center prospective study.

BACKGROUND: The present study evaluated the clinical outcomes and safety of expansive open-door laminoplasty, when securing with C4 - C6 lateral mass screw and fusion. METHODS: A total of 110 patients with cervical spondylotic myelopathy (CSM) were enrolled. There were 88 male and 22 female, with mean age at 60.55 ± 10.95 years. All of the patients underwent expansive open-door laminoplasty with unilateral or bilateral C4-6 lateral mass screws fixation and fusion. Clinical data, including age, gender, operation-related information, pre- and post-operation Japanese Orthopedic Association (JOA) scores, and cervical curvatures were collected. RESULTS: The mean follow-up time of the cohort was 13.61 ± 9.53 months. Among the 110 patients, 33 of them were allocated to Unilateral group, and 77 of them were in Bilateral group. The mean JOA score of the 110 patients before surgery was 10.07 ± 2.39, and the score was improved significantly to 12.85 ± 2.45 after surgery. There were no reported cases of neurological deterioration or symptom worsening. Patients in both the Unilateral group and Bilateral groups had significant improvement of JOA scores. Among all patients, the most frequently observed complications were axial symptoms (n = 7). The average preoperative cervical curvature among all patients was 15.17 ± 5.26, and the post-surgery curvature was 14.41 ± 4.29. Similar observations were found between Unilateral and Bilateral groups. CONCLUSION: The modified surgical approach provided satisfactory clinical outcome in patients with CSM. The unilateral and bilateral fixation appeared to provide similar outcomes, in terms of cervical curvature maintenance and improvement of clinical symptoms. However, the examination of the exact differences between the two fixation methods await further biomechanical studies.

Ulinastatin May Significantly Improve Postoperative Cognitive Function of Elderly Patients Undergoing Spinal Surgery by Reducing the Translocation of Lipopolysaccharide and Systemic Inflammation.

Background: Studies have shown that perioperative inflammatory response is one of the important factors that caused postoperative cognitive dysfunction (POCD). Ulinastatin is a broad-spectrum protease inhibitor that inhibits inflammatory. We investigated the effects of ulinastatin on inflammatory response and early postoperative cognitive function in elderly patients undergoing spinal surgery. Methods: This clinical trial was approved by the Xuanwu Hospital Ethical Committee (Registration number: ChiCTR-IPR-16008931). Sixty elderly patients undergoing elective spinal surgery with American Society of Anesthesiologists (ASA) status of I-II were randomized into ulinastatin and control groups; total intravenous anesthesia was performed. The elderly patients in ulinastatin group underwent intravenous infusion of ulinastatin 10,000 units/kg following anesthesia induction and before surgical incision, and 5000 units/kg on post-operative days 1 and 2. Cognitive function was determined with Montreal Cognitive Assessment (MOCA) test preoperatively and on post-operative day 7 by a neurologist. Serum lipopolysaccharide (LPS), interleukin-6 (IL-6), C-reactive protein (CRP), and matrix metalloprotease-9 (MMP-9) concentration levels were measured at baseline, the end of surgery, and on post-operative days 1 and 3. Results: All elderly patients completed the study. Ulinastatin infusion significantly reduced the incidence of POCD in elderly patients undergoing spine surgery (ulinastatin group 16% vs. control group 43%, χ 2 = 5.079, P = 0.024, P < 0.05). The elderly patients in ulinastatin group exhibited lower serum LPS, IL-6, CRP, and MMP-9 concentrations, as well as a shortened peak value duration, compared with those in the control group following surgery (P < 0.05). Conclusion: Systemic inflammation and translocation of LPS were inhibited by the infusion of ulinastatin in elderly patients undergoing spinal surgery. The anti-inflammation intervention with ulinastatin can significantly improve the elderly patients' postoperative cognitive function.

Serum CRP and urinary trypsin inhibitor implicate postoperative cognitive dysfunction especially in elderly patients.

PURPOSE: Postoperative cognitive dysfunction (POCD) characterized as the decline of memory and executive function after major surgery is not well illustrated. The aim of this study is to discover whether inflammatory cytokines and urinary trypsin inhibitor (uTi) contribute to the development of POCD. METHOD: Sixty-three patients undergoing lumber discectomy and 47 age-matched control volunteers were involved in this study. The level of C-reaction protein (CRP) and uTi/urine creatinine (Ucr) was measured by immunoturbidimetry and enzyme-inhibition assay, respectively. Meanwhile, ELISA was involved to detect the level of IL-6, IL-10, MMP-9 in serum. Montreal Cognitive Assessment (MoCA) test was used to determine the cognitive decline of the patients and age-matched controls. RESULT: In POCD group, the level of IL-6, IL-10, CRP, MMP-9 in serum and uTi /Ucr in urine was significantly higher than that in the group without POCD. The POCD was more frequently observed in elderly group than in the middle-aged group (43.75% versus 19.35%, p = 0.038). After logistic regression analysis adjusted by the age, only serum CRP at 72 h postoperation and urinary uTi /Ucr at 24 h postoperation were the independent risk factors of POCD. CONCLUSION: Age-related increasing proinflammatory postoperation may result in higher occurrence of POCD in the elderly. Additionally, patients with extremely high concentrations of CRP in serum at 72 h postoperation and uTi /Ucr in urine at 24 h postoperation are more likely to experience POCD, especially in the elderly.

Superconductivity at 44 K in K intercalated FeSe system with excess Fe.

We report here that a new superconducting phase with much higher Tc has been found in K intercalated FeSe compound with excess Fe. We successfully grew crystals by precisely controlling the starting amount of Fe. Besides the superconducting (SC) transition at ~30 K, we observed a sharp drop in resistivity and a kink in susceptibility at 44 K. By combining thermodynamic measurements with electron spin resonance (ESR), we demonstrate that this is a new SC transition. Structural analysis unambiguously reveals two phases coexisting in the crystals, which are responsible respectively for the SC transitions at 30 and 44 K. The structural experiments and first-principles calculations consistently indicate that the 44 K SC phase is close to a 122 structure, but with an unexpectedly large c-axis of 18.10 Å. We further find a novel monotonic dependence of the maximum Tc on the separation of neighbouring FeSe layers.

Structure and magnetism of S = 1/2 kagome antiferromagnets NiCu3(OH)6Cl2 and CoCu3(OH)6Cl2.

We have successfully synthesized S = 1/2 kagome antiferromagnets MCu(3)(OH)(6)Cl(2) (M = Ni and Co) by a hydrothermal method with a rotating pressure vessel. Structural characterization shows that both compounds have similar crystal structure to ZnCu(3)(OH)(6)Cl(2) with R3m symmetry. As with ZnCu(3)(OH)(6)Cl(2), the compounds show no obvious hysteresis at 2 K. A spin-glass transition is found in both NiCu(3)(OH)(6)Cl(2) and CoCu(3)(OH)(6)Cl(2) at low temperatures (6.0 and 3.5 K respectively) by AC susceptibility measurements. This indicates no long-range magnetic order and a strong spin frustration. The substitution of Zn(2+) by magnetic ions Ni(2+) or Co(2+) effectively enhances the interlayer exchange coupling and changes the ground state of the kagome spin system.

The combined stress effects of atrazine and cadmium on the earthworm Eisenia fetida.

To assess the combined toxic effects of atrazine and cadmium on earthworms, specimens of Eisenia fetida were exposed in artificial soil to three concentrations of atrazine (0, 0.5, and 2.5 mg kg(-1)) and a range of concentrations of cadmium (Cd; 0, 0.03, 0.3, and 3.0 mg kg(-1)) both singly and as mixtures. The DNA damage and internal atrazine and cadmium concentrations were assessed in earthworms on days 7, 14, 21, and 28 of the treatment. The results showed that the olive tail moments (OTMs) at individual atrazine and cadmium concentrations were significantly higher than those of the controls (p < 0.01). As exposure to atrazine or cadmium progressed, the OTMs increased and the maximum value occurred on day 28. In all combined treatments, the OTMs were much less than those of the sum of individual atrazine and cadmium OTMs, suggesting that the combined effects of atrazine and cadmium were less than additive. The less than additive toxicity of atrazine and cadmium might be due to the formation of atrazine-cadmium complexes or the activation of detoxification isozymes. Moreover, there was a significant correlation between internal atrazine or cadmium concentrations and DNA damage in most exposures, indicating that body residues were consistent with toxicity response.

Prevalence of human papillomavirus and cervical intraepithelial neoplasia in China: a pooled analysis of 17 population-based studies.

High-risk (HR) human papillomavirus (HPV) prevalence has been shown to correlate well with cervical cancer incidence rates. Our study aimed to estimate the prevalence of HR-HPV and cervical intraepithelial neoplasia (CIN) in China and indirectly informs on the cervical cancer burden in the country. A total of 30,207 women from 17 population-based studies throughout China were included. All women received HPV DNA testing (HC2, Qiagen, Gaithersburg, MD), visual inspection with acetic acid and liquid-based cytology. Women positive for any test received colposcopy-directed or four-quadrant biopsies. A total of 29,579 women had HR-HPV testing results, of whom 28,761 had biopsy confirmed (9,019, 31.4%) or assumed (19,742, 68.6%) final diagnosis. Overall crude HR-HPV prevalence was 17.7%. HR-HPV prevalence was similar in rural and urban areas but showed dips in different age groups: at age 25-29 (11.3%) in rural and at age 35-39 (11.3%) in urban women. In rural and urban women, age-standardized CIN2 prevalence was 1.5% [95% confidence interval (CI): 1.4-1.6%] and 0.7% (95% CI: 0.7-0.8%) and CIN3+ prevalence was 1.2% (95% CI: 1.2-1.3%) and 0.6% (95% CI: 0.5-0.7%), respectively. Prevalence of CIN3+ as a percentage of either all women or HR-HPV-positive women steadily increased with age, peaking in 45- to 49-year-old women. High prevalence of HR-HPV and CIN3+ was detected in both rural and urban China. The steady rise of CIN3+ up to the age group of 45-49 is attributable to lack of lesion removal through screening. Our findings document the inadequacy of current screening in China while indirectly raising the possibility that the cervical cancer burden in China is underreported.

Thermal decomposition of the solid phase of nitromethane: ab initio molecular dynamics simulations.

The Car-Parrinello molecular dynamics simulations were employed to investigate thermal decomposition of the solid nitromethane. It is found that it undergoes chemical decomposition at about 2200 K under ambient pressure. The initiation of reactions involves both proton transfer and commonly known C-N bond cleavage. About 75 species and 100 elementary reactions were observed with the final products being H2O, CO2, N2, and CNCNC. It represents the first complete simulation of solid-phase explosive reactions reported to date, which is of far-reaching implication for design and development of new energetic materials.

Human papillomavirus testing and cervical cytology in primary screening for cervical cancer among women in rural China: comparison of sensitivity, specificity, and frequency of referral.

The causal relationship between persistent high-risk human papillomavirus infection and cervical cancer is widely accepted. HR-HPV DNA testing, alone or in combination with Pap smear testing, may have a role in primary screening. The screening results (VIA, VILI, Pap, and HR-HPV DNA) of 9,057 women in rural China were analyzed to determine the screening performance for the detection of CIN3+. All screening strategies had comparable AUCs (0.9). Cotesting strategies had the overall highest sensitivity for CIN3+ (99.4%), followed by HR-HPV DNA testing alone (96.3%), Pap alone (80.2%), and reflex testing (75.4%). Reflex testing had the highest specificity (96.7%), followed by Pap alone (93.3%), HR-HPV DNA testing alone (85.5%), and both cotesting strategies (LSIL: 84.8%, HSIL: 84.8%). Of the single-test strategies, HR-HPV DNA testing had a higher sensitivity (96.3% vs. 80.2%) compared with Pap testing. The specificity of the Pap test was higher (93.3% vs. 85.5%) and it had a lower percent referred for colposcopy (7.8% vs. 15.8%) than HR-HPV DNA testing. HR-HPV DNA testing with a 10.0 cutoff point (relative light units/cutoff ratio) had a sensitivity (85.2%) and specificity (90.6%) estimate comparable to Pap testing. A single-test primary screening strategy with adequate performance would permit less frequent screening and be most appropriate. Of the primary screening strategies investigated in this setting in China, the performance of HR-HPV DNA testing with an increased cutoff-point might best meet these criteria.