Arginase from Priestia megaterium and the Effects of CMCS Conjugation on Its Enzymological Properties.

Arginase has shown promising potential in treating cancers by arginine deprivation therapy; however, low enzymatic activity and stability of arginase are impeding its development. This study was aimed to improve the enzymological properties of a marine bacterial arginase by carboxymethyl chitosan (CMCS) conjugation. An arginase producing marine bacterium Priestia megaterium strain P6 was isolated and identified. The novel arginase PMA from the strain was heterologously expressed, purified, and then conjugated to CMCS by ionic gelation with calcium chloride as the crosslinking agent. Enzymological properties of both PMA and CMCS-PMA conjugate were determined. The optimum temperature for PMA and CMCS-PMA at pH 7 were 60 °C and 55 °C, respectively. The optimum pH for PMA and CMCS-PMA at 37 °C were pH 10 and 9, respectively. CMCS-PMA showed higher thermostability than PMA over 55-70 °C and higher pH stability over pH 4-11 with the highest pH stability at pH 7. At 37 °C and pH of 7, i.e., around the human blood temperature and pH, CMCS-PMA was higher than the free PMA in enzymatic activity and stability by 24% and 21%, respectively. CMCS conjugation not only changed the optimum temperature, optimum pH, and enzymatic activity of PMA, but also improved its pH stability and temperature stability, and thus made it more favorable for medical application.

[Analysis of chemical constituents in Shenmai Injection by LC-Q-TOF-MS and LC-IT-MS].

The chemical constituents in Shenmai Injection(SMI) were qualitatively analyzed by using liquid chromatography/quadrupole time-of-flight mass spectrometry(LC-Q-TOF-MS) and liquid chromatography-ion trap-mass spectrometry(LC-IT-MS). The analysis was performed on an Agilent Zorbax SB-C_(18)(4.6 mm×250 mm, 5 µm) and gradient elution was carried out with 0.05% formic acid solution-acetonitrile as mobile phase at a flow rate of 0.6 mL·min~(-1) and a column temperature of 30 ℃. Mass spectrometry data of the components in SMI were collected in negative ion mode. The structures of components were speculated and identified by analyzing mass spectrometry data, comparing with standards, and referring to related literature. A total of 64 components in SMI were estimated, and the structures were confirmed in 16 of them by comparison with standards. Fifty-six compounds derived from Ginseng Radix et Rhizoma Rubra included 34 protopanaxadiol ginsenosides, 19 protopanaxatriol ginsenosides, 1 oleanane ginsenosides and 2 other glycosides. Eight compounds derived from Ophiopogonis Radix included 7 steroidal saponins, and 1 monoterpene glycoside. The results of this study would provide an important theoretical basis for the improvement of the quality control standards and the discovery of effective constituents in SMI.

Acute restraint stress triggers progesterone withdrawal and endometrial breakdown and shedding through corticosterone stimulation in mouse menstrual-like model.

Stress impacts the reproductive axis at the level of the hypothalamus and the pituitary gland, which exert an effect on the ovary. Menstruation is regulated by the hypothalamic-pituitary-ovary (HPO) axis. However, the role of stress in menstruation remains unclear. The objective of this study was to explore the role of stress in endometrial breakdown and shedding, using the pseudopregnant mouse menstrual-like model. Female mice were mated with vasectomized males and labeled day 0.5, upon observation of a vaginal seminal plug. On day 3.5, decidualization was induced in pseudopregnant mice using arachis oil. On day 5.5, pseudopregnant mice with artificial decidualization were placed in restraint tubes for 3 h. The findings indicated that acute restraint stress resulted in the disintegration of the endometrium. While corticosterone concentration in the serum increased significantly due to restraint stress, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and progesterone (P4) levels in the serum decreased significantly. An endometrial histology examination indicated that progesterone implants may rescue P4 decline caused by acute stress and block endometrium breakdown and shedding. In addition, mice were treated with metyrapone, an inhibitor of corticosterone synthesis, 1 h prior to being subjected to restraint stress. Interestingly, metyrapone not only inhibited stress-induced endometrium breakdown and shedding, but also prevented stress-induced reduction of P4, LH and FSH. Furthermore, real-time PCR and western blot showed that mRNA and protein expression of CYP11A1 (cytochrome P450, family 11, subfamily A, polypeptide 1) and steroidogenic acute regulatory protein (StAR), the two rate-limiting enzymes for progesterone synthesis in the ovary, decreased following acute stress. But metyrapone prevented the reduction of StAR expression induced by restraint stress. Overall, this study revealed that acute stress results in an increase in corticosterone, which may inhibit LH and FSH release in the serum and CYP11A1 and StAR expression in the ovary, which finally leads to the breakdown and shedding of the endometrium. These experimental findings, based on the mouse model, may enable further understanding of the effects of stress on menstruation regulation and determine the potential factors affecting stress-associated menstrual disorders.

Gender, Age, and Concomitant Diseases of Colorectal Diverticulum in China: A Study of 7,964 Cases.

AIM: To analyze the epidemiological features of colorectal diverticulum (CRD) in China. METHODS: We retrospectively analyzed CRD patients in 8 tertiary hospitals located in 5 regions of China from 2000 to 2016. The detection rates, number and distribution, demographic information, concomitant disorders, and their associations were investigated. RESULTS: Of 3,446,118 cases, 7,964 (2.3%) were CRD with a mean age of 56 years (11-92 years). The detection rate increased yearly and with increasing age. Males had a higher detection rate than females (3.0 vs. 1.47%, p < 0.01) and 1.8-times higher increase rate. The detection rate increased with age; however, females of > 60 years had a 2.8-times increasing rate than males. CRD occurred most frequently in the right-side colon, followed by rectum. Multiple diverticula were common in males and increased with age, with a 3-times higher increase rate than single lesion. Single-segment CRD occurred more frequently in males than in females (80.1 vs. 76.4%, p < 0.01). Concurred colon polyps were seen in 51.05% cases. CONCLUSION: CRD detection rates increased annually and with age, particularly in senior females in China. Multiple diverticula were common in males and increased with age. CRD was predominant in the right-side colon. Polyps are the most common comorbidity associated with CRD.

Variations of thermoelectric performance by electric fields in bilayer MX2 (M = W, Mo; X = S, Se).

A gate electrode is usually used to controllably tune the carrier concentrations, further modulating the electrical conductivity and the Seebeck coefficient to obtain the optimum thermoelectric figure of merit (ZT) in two-dimensional materials. On the other hand, it is necessary to investigate how an electric field induced by a gate voltage affects the electronic structures, further determining the thermoelectric properties. Therefore, by using density functional calculations in combination with Boltzmann theory, the thermoelectric properties of bilayer MX2 (M = W, Mo; X = S, Se) with or without a 1 V nm-1 perpendicular electric field are comparatively investigated. First of all, the variations of the electrical conductivity (σ), electron thermal conductivity and Seebeck coefficient (S) with the carrier concentration are studied. Due to the trade-off relationship between S and σ, there is an optimum concentration to obtain the maximum ZT, which increases with the temperature due to the enhancement of the Seebeck coefficient. Moreover, N-type bilayers have larger optimum ZTs than P-type bilayers. In addition, the electric field results in the increase of the Seebeck coefficient in low hole-doped MS2 bilayers and high hole-doped MSe2 bilayers, thus leading to similar variations in ZT. The optimum ZTs are reduced from 2.11 × 10-2, 3.19 × 10-2, 2.47 × 10-2, and 2.58 × 10-2 to 1.57 × 10-2, 1.51 × 10-2, 2.08 × 10-2, and 1.43 × 10-2 for the hole-doped MoS2, MoSe2, and WSe2 bilayers, respectively. For N-type bilayers, the electric field shows a destructive effect, resulting in the obvious reduction of the Seebeck coefficient in the MSe2 layers and the low electron-doped MS2 bilayers. In electron-doped bilayers, the optimum ZTs will decrease from 3.03 × 10-2, 6.64 × 10-2, and 6.69 × 10-2 to 2.81 × 10-2, 3.59 × 10-2, and 4.39 × 10-2 for the MoS2, MoSe2, and WSe2 bilayers, respectively.

Flatbands in 2D boroxine-linked covalent organic frameworks.

Density functional calculations have been performed to analyze the electronic and mechanical properties of a number of 2D boroxine-linked covalent organic frameworks (COFs), which are experimentally fabricated from di-borate aromatic molecules. Furthermore, the band structures are surprising and show flat-band characteristics which are mainly attributed to the delocalized π-conjugated electrons around the phenyl rings and can be better understood within aromaticity theories. Next, the effects of branch sizes and hydrostatic strains on their band structures are systematically considered within generalized gradient approximations. It is found that their band gaps will start to saturate when the branch size reaches 9. For boroxine-linked COFs with only one benzene ring in the branch, the band gap is robust under compressive strain while it decreases with the tensile strain increasing. When the branch size is equal or greater than 2, their band gaps will monotonously increase with the strain increasing in the range of [-1.0, 2.0] Å. All boroxine-linked COFs are semiconductors with controllable band gaps, depending on the branch length and the applied strain. In comparison with other 2D materials, such as graphene, hexagonal boron nitride, and even γ-graphyne, all boroxine-linked COFs are much softer and even more stable. That is, they can maintain the planar features under a larger compressive strain, which means that they are good candidates in flexible electronics.

Thermoelectric properties of fullerene-based junctions: a first-principles study.

This study is built on density functional calculations in combination with the non-equilibrium Green's function, and we probe the thermoelectric transport mechanisms through C60 molecules anchored to Al nano-electrodes in three different ways, such as, the planar, pyramidal, and asymmetric surfaces. When the electrode is switched from the planar and pyramidal surfaces, the electrical conductance (σ) and electron's thermal conductance (κel) decrease almost two orders of magnitude due to the reduction of the molecule-electrode contact coupling, whereas the Seebeck coefficients (S) are reduced by ∼55%. Furthermore, the maximum electron's thermoelectric figure of merit (ZelT = S2σT/κel, assuming a vanishing phonon's thermal conductance) is about 0.12 in the asymmetric junction. In particular, all σ, S, κel, and ZelT increase along with the average temperature (T) in all C60-junctions, although their growth is really quite negligible in the pyramidal junction because the Fermi level is far away from the frontier orbitals. In addition, when the strain increases from the compressive (-1.0 Å) to tensile (1.0 Å) strain, the Seebeck coefficient in the planar junction increases drastically, while the Seebeck coefficients in the asymmetric and pyramidal junctions reach their maximum values at 0.2 Å tensile and -0.4 Å compressive strains, respectively. This is because the Seebeck coefficient is inversely proportional to the magnitudes and proportional to the slopes of the transmission spectrum around the Fermi level. Finally, it is found that the shift of the Fermi level is an effective scheme to obtain the maximum ZelT of any molecular junction, including fullerene-based junctions.

Anti-inflammatory Terpenoids from the Leaves and Twigs of Dysoxylum gotadhora.

Nine new terpenoids (1-3, 5-10), including three cyclolanostane triterpenoids (1-3) and six isopimarane diterpenoids (5-10), along with six known terpenoids (4, 11-15), were isolated from the leaves and twigs of Dysoxylum gotadhora. Compound 1 represents a class of rare natural 21,24-epoxy cyclolanostane-type triterpenoids, and compounds 2 and 3 are the first examples of 21,25-epoxy cyclolanostane-type triterpenoids. Compounds 1, 2, 4, 8, and 15 exhibited noteworthy inhibition of nitric oxide production induced by lipopolysaccharide in RAW 264.7 cells with IC50 values of 25.5, 41.5, 27.4, 14.5, and 45.2 µM, respectively.

[Enhancement effect of double-beam laser processed aqueous solution on ICP emission spectrum].

In order to change the physical properties of aqueous solution and improve the radiation intensity of the ICP emission spectrum, the effects of different laser power density and irradiation time on the surface tension and viscosity of aqueous solution were investigated by using near infrared laser at 976 nm and CO2 laser at 10. 6 µm to irradiate aqueous solution orthogonally, then the enhancement of ICP spectral intensity with processed solution was discussed. The results showed that the surface tension and viscosity of aqueous solution reduced by 42. 13% and 14. 03% compared with the untreated, and the atomization efficiency increased by 51.26% at the laser power density 0. 265 7 W . cm-2 of 976 nm and 0. 206 9 W . cm-2 of CO2 laser with 40 min irradiation time. With the optimized aqueous solution introduced into the ICP source, the spectral line intensity of sample elements As, Cd, Cr, Hg and Pb was enhanced by 46.29%, 94. 65%, 30. 76%, 33.07% and 94. 58% compared to the untreated aqueous solution, while the signal-to-background ratio increased by 43. 84%, 85. 35%, 28. 71%, 34. 37% and 90. 91%, respectively. Plasma temperature and electron density also increased by 5. 94% and 1. 18% respectively. It is obvious that the method of double-beam laser orthogonal irradiation on solution can reduce the surface tension and viscosity of aqueous solution significantly, and raise the radiationintensity of ICP source, and will provide a better condition for detecting the trace heavy metal elements in water samples.

[Research achievements on biological activities of calycosin].

Calycosin, which is a kind of typical phytoestrogen, can bind with estrogen receptor and produce estrogen-like effects. Calycosin were reported to have antioxidant, anti-osteoporosis, anti-tumor and immunomodulating activities. This review covers biological activities and its mechanism of calycosin. It will provide a useful reference for clinical research and rational utilization of monomericompound.

[Primary investigation of formation and genetic mechanism of land subsidence based on PS-InSAR technology in Beijing].

The present paper adopts permanent scatterer interferometric synthetic aperture radar(PS-InSAR) technique to obtain land subsidence information in Beijing plain area. Then, combined with the time series of meteorological data, groundwater dynamic monitoring data, interferometric data and geological structure data, the formation and evolution mechanism of land subsidence were revealed. The results show that (1) Beijing regional land subsidence characteristics are obvious, more land subsidence funnel areas are interconnected, the settlement is influenced by rainfall recharge and exhibits seasonal fluctuation characteristics; (2) The land subsidence center and groundwater drawdown funnel centre are not fully consistent, unconfined aquifer and shallow confined aquifer are the major contribution factors and have greater impact on the land subsidence; (3) Land subsidence mainly occurred in the clay layer with a thickness of 50-70 m; (4) Land subsidence caused by tectonic controls is significant and the deformation gradient is great on both sides of the fault.

[A new phthalide from angelicae sinensis radix].

Angelicae Sinensis Radix, dried roots of Angelicae sinensis, is a well-known traditional Chinese medicine. Six compounds were isolated and purified by silica gel and preparative HPLC. According to physicochemical properties and spectral data, the compounds were identified as senkyunolide H-7-acetate (1), o-phthalic acid (2), diisobutyl phthalate (3), p-hydroxyphenylethanol ferulate (4), ferulic acid (5) and coniferylferulate (6). Compound 1 was a new one.

[Identification of constituents in Suanzaoren tang by LC-Q-TOF-MS and LC-IT-MS].

LC-Q-TOF-MS and LC-IT-MS in positive and negative ion mode were applied to simultaneously characterize the constituents in Suanzaoren tang. Analysis was performed on an Agilent Zorbax SB-C18, Rapid Resolution HT column(4.6 mmx 50 mm, 1. 8 micro m) with gradient elution of acetonitrile(A) -aqueous solution containing 0. 05% formic acid(B) at a flow rate of 0. 6 mL min(-1) and the column temperature was 30 degreesC. By comparing MS fragmentation, accurate molecular weight, literature date and standard compounds information, a total of48 compounds were successfully identified or speculated. The origins of these compounds were assigned to the corresponding Chinese medicine. Thirty-one compounds were reported in Suanzaoren tang for the first time. LC-Q-TOF-MS combined with LC-IT-MS is a simple and rapid tool for the identification of constituents of Suanzaoren tang, and the results could provide evidence for the research on quality combined and effective constituents of Suanzaoren tang.

Correction: Chen et al. Multifunctional Injectable Hydrogel Loaded with Cerium-Containing Bioactive Glass Nanoparticles for Diabetic Wound Healing. Biomolecules 2021, 11, 702.

The authors would like to replace Figure 4A of the following published paper [...].

Oral arsenic plus imatinib versus imatinib solely for newly diagnosed chronic myeloid leukemia: a randomized phase 3 trial with 5-year outcomes.

PURPOSE: The synergistic effects of combining arsenic compounds with imatinib against chronic myeloid leukemia (CML) have been established using in vitro data. We conducted a clinical trial to compare the efficacy of the arsenic realgar-indigo naturalis formula (RIF) plus imatinib with that of imatinib monotherapy in patients with newly diagnosed chronic phase CML (CP-CML). METHODS: In this multicenter, randomized, double-blind, phase 3 trial, 191 outpatients with newly diagnosed CP-CML were randomly assigned to receive oral RIF plus imatinib (n = 96) or placebo plus imatinib (n = 95). The primary end point was the major molecular response (MMR) at 6 months. Secondary end points include molecular response 4 (MR4), molecular response 4.5 (MR4.5), progression-free survival (PFS), overall survival (OS), and adverse events. RESULTS: The median follow-up duration was 51 months. Due to the COVID-19 pandemic, the recruitment to this study had to be terminated early, on May 28, 2020. The rates of MMR had no significant statistical difference between combination and imatinib arms at 6 months and any other time during the trial. MR4 rates were similar in both arms. However, the 12-month cumulative rates of MR4.5 in the combination and imatinib arms were 20.8% and 10.5%, respectively (p = 0.043). In core treatment since the 2-year analysis, the frequency of MR4.5 was 55.6% in the combination arm and 38.6% in the imatinib arm (p = 0.063). PFS and OS were similar at five years. The safety profiles were similar and serious adverse events were uncommon in both groups. CONCLUSION: The results of imatinib plus RIF as a first-line treatment of CP-CML compared with imatinib might be more effective for achieving a deeper molecular response (Chinadrugtrials number, CTR20170221).

[Creating baby-friendly neonatal intensive care units].

Most expectant parents anticipate giving birth to a healthy newborn. Admission of a neonate to a neonatal intensive care unit (NICU) is thus nearly always a significant and negative shock to parents and family members. We derived core concepts for this article from the World Health Organization/United Nations Children's Fund (WHO/UNICEF)'s Baby Friendly Hospital Initiative: Revised, updated, and expanded for integrated care (2009). This framework document advocates expanding to NICUs guidelines that were originally developed for maternity units. This paper reviews the importance of breastfeeding to the mother-baby dyad and family integration. We suggest how to build a breastfeeding-friendly environment within the NICU using 10 steps that adhere to the NEO-BFHI's three "Guiding Principles". The proposed environment gives special emphasis to providing continued and unlimited kangaroo care, creating a family-centered NICU design, implementing an effective milk expression and monitoring plan, and respecting mothers' individual needs. Suggestions are provided as a reference to government policymakers and medical centers to facilitate the creation of breastfeeding-friendly environments in NICUs.

Constructing quasi-layered and self-hole doped SnSe oriented films to achieve excellent thermoelectric power factor and output power density.

Thermoelectric (TE) technology can achieve the mutual conversion between electric energy and waste heat, and it has exhibited great prospects in multifunctional energy applications to alleviate the energy crisis. In the recent decade, SnSe has been explored widely because of its potentially high energy harvesting efficiency, green nature, and low cost. However, the relatively poor power factor (PF) derived from the intrinsic low carrier concentration (∼1017 cm-3) limits the output power density of the stoichiometric SnSe devices. Therefore, the advancement of novel optimization strategies for controlling carrier concentration is of utmost importance. Besides, compared with 3D bulks, 2D thin films are more compatible with modern semiconductor technology and have unique advantages in the construction and application of TE micro- and nano-devices. In this study, post-selenization technology were applied to increase the carrier concentration of the a-axis oriented SnSe epitaxial films utilizing the charge transfer and self-hole doped effects. The quasi-layered and self-hole doped films exhibited a high power factor of ∼5.9 µW cm-1 K-2 at 600 K along the in-plane direction when the carrier concentration is enhanced to ∼1018 cm-3 by increasing the selenization time to ∼20 min. The TE generator composed of four P-type film legs demonstrated the ultrahigh maximum power density of ∼83, ∼838 µW cm-2 at the temperature difference of ∼50 and ∼90 K, respectively. Post-selenization can effectively optimize the carrier concentration of SnSe-based materials, which is also feasible to other anion deficient TE films.

Hereditary hemorrhagic telangiectasia involving portal venous system: A case report and review of the literature.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disorder with an incidence of approximately 1 in 5000 in the general population. It is characterized by vasodilation, which affects specific organs, such as the skin, mucous membranes, brain, lungs, gastrointestinal tract, liver, and others. However, HHT rarely involves the portal venous system to cause serious clinical complications. CASE SUMMARY: A 68-year-old woman was admitted to the emergency department due to four consecutive days of abdominal pain and bloody stool and was subsequently diagnosed with HHT. Computed tomography angiography confirmed the presence of an arteriovenous fistula (AVFs). Considering this specific manifestation, whole exome sequencing was performed. After a comprehensive evaluation, a selective superior mesenteric artery embolization was prioritized to avoid intestinal ischemia. The postoperative symptoms of the patient were quickly relieved. Unfortunately, two months post-procedure the patient died from intestinal necrosis and abdominal infection related to remaining AVFs. CONCLUSION: For patients with diffuse superior mesenteric AVFs, selective mesenteric arterial embolization may lead to positive short-term outcomes.

[The value of esophageal intrapapillary capillary loop visualized by magnifying narrow-band imaging endoscopy in diagnosing esophageal mucosal pathology].

OBJECTIVE: To investigate the diagnostic potential of magnifying narrow-band imaging endoscopy (NBI-ME) for different intrapapillary capillary loop (IPCL) for the diagnosis of esophageal lesion. METHODS: Patients with abnormal esophageal mucosa found by white light gastroscopy in digestive endoscopy center, Chinese PLA General Hospital during the period of November 2009 to November 2010 were enrolled in this study. IPCL was observed and divided into different types by NBI-ME. Histopathology of biopsy or endoscopic submucosal dissection (ESD) specimens was evaluated and used as the gold standard to evaluate the diagnostic value of NBI-ME for IPCL. RESULTS: A total of 146 lesions from 145 subjects with esophageal mucosa abnormal were collected. Among them, 88 were pathology-proven inflammation, 5 were pathology-proven esophageal cancers, 20 were pathology-proven low intraepithelial neoplasia (LIN) and 33 were pathology-proven high intraepithelial neoplasia (HIN) detected with NBI-ME. By a per-lesion analysis, the accuracy of inflammation and cancer were 100% (88/88) and 7/7. For the sensitivity, specificity, accuracy, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio of LIN and HIN were 7/10, 69.8% (30/43), 69.8% (37/53), 35.0% (7/20), 90.9% (30/33), 12.5% (70/559), 2.3% (30/1290) and 87.1% (27/31), 72.7% (16/22), 81.1% (43/53), 81.8% (27/33), 80.0% (16/20), 634.1% (837/132) and 35.2% (124/352), respectively. CONCLUSIONS: NBI-ME can classify the different esophageal IPCL. Higher diagnostic accuracy of IPCL indicates the feasibility of NBI-ME for the efficacious diagnosis of esophageal inflammation and cancer. There is the higher diagnostic accuracy of HIN than LIN.