Genetic selection and intensive nutrition for increased growth rate in meat-type ducks has resulted in an imbalance between pectorales increment and sternal mass, which is detrimental to productivity ...and welfare. Reducing body weight and increasing sternal mass probably reverses these adverse effects. Therefore, 2 experiments (Expt.) were conducted to investigate the effects of 25-hydroxycholecalciferol (25-OH-D3), a vitamin D3 metabolites, on sternal mass. In Expt. 1, 512 1-day-old male ducks were randomly assigned to 4 low-nutrient density diets and received following treatments in a 2 × 2 factorial arrangement: (i) NRC or China Agricultural industry standards (NY/T) vitamin premixes and (ii) 0.069 mg/kg 25-HyD in feed or not. At 49 D of age, regardless of 25-OH-D3, NY/T vitamin regimen inhibited bone turnover and consequently increased sternal trabecular bone volume and mineral deposition compared with NRC vitamin premix. Supplementing 25-OH-D3 to NRC but not NY/T vitamin regimen significantly improved sternal microarchitecture and mineral content, which companied by decreased serum bone resorption markers concentration, as well as downregulation of the gene expressions of osteoclast differentiation and activity. In Expt. 2, 256 1-day-old male ducks were fed a standard nutrient density diet contained NRC vitamin premix with 0 or 0.069 mg/kg of 25-OH-D3. Results also showed that 25-OH-D3 treatment significantly improved sternal mineral accumulation and microarchitecture, along with decreasing osteoblast and osteoclast numbers in bone surface, declining serum bone turnover markers levels, and increasing serum Ca concentration. Collectively, these findings indicated that the dietary administration of 25-OH-D3 increased sternal mass in NRC vitamin diet by suppressing bone resorption in 49-day-old meat duck.
Properties of proton resonances in \(^{18}\)Ne have been investigated efficiently by utilizing a technique of proton resonant elastic scattering with a \(^{17}\)F radioactive ion (RI) beam and a ...thick proton target. A 4.22~MeV/nucleon \(^{17}\)F RI beam was produced via a projectile-fragmentation reaction, and subsequently separated by a Radioactive Ion Beam Line in Lanzhou ({\tt RIBLL}). Energy spectra of the recoiled protons were measured by two sets of \(\Delta\)E-E silicon telescope at center-of-mass scattering angles of $\theta_{c.m.}$$\approx\(175\){^\circ}$$\pm\(5\){^\circ}\(, \)\theta_{c.m.}$$\approx\(152\){^\circ}$$\pm\(8\){^\circ}\(, respectively. Several proton resonances in \)^{18}\(Ne were observed, and their resonant parameters have been determined by an \)R\(-matrix analysis of the differential cross sections in combination with the previous results. The resonant parameters are related to the reaction-rate calculation of the stellar \)^{14}\(O(\)\alpha\(,\)p\()\)^{17}\(F reaction, which was thought to be the breakout reaction from the hot CNO cycles into the \)rp\(-process in x-ray bursters. Here, \)J^\pi\(=(3\)^-\(, 2\)^-\() are tentatively assigned to the 6.15-MeV state which was thought the key 1\)^-\( state previously. In addition, a doublet structure at 7.05 MeV are tentatively identified, and its contribution to the resonant reaction rate of \)^{14}\(O(\)\alpha\(,\)p\()\)^{17}\(F could be enhanced by at least factors of about 4\)\sim$6 in comparison with the previous estimation involving only a singlet. The present calculated resonant rates are much larger than those previous values, and it may imply that this breakout reaction could play a crucial role under x-ray bursters conditions.
Aims
Poly‐γ‐glutamic acid (γ‐PGA) is an excellent water‐soluble biosynthesis material. To confirm the rate‐limiting steps of γ‐PGA biosynthesis pathway, we introduced a heterologous Bacillus strain ...pathway and employed an enzyme‐modulated dismemberment strategy in Escherichia coli.
Methods and Results
In this study, we heterologously introduced the γ‐PGA biosynthesis pathway of two laboratory‐preserved strains—Bacillus amyloliquefaciens FZB42 and Bacillus subtilis 168 into E. coli, and compared their γ‐PGA production levels. Next, by changing the plasmid copy numbers and supplying sodium glutamate, we explored the effects of gene expression levels and concentrations of the substrate l‐glutamic acid on γ‐PGA production. We finally employed a two‐plasmid induction system using an enzyme‐modulated dismemberment of pgsBCAE operon to confirm the rate‐limiting genes of the γ‐PGA biosynthesis pathway.
Conclusion
Through heterologously over‐expressing the genes of the γ‐PGA biosynthesis pathway and exploring gene expression levels, we produced 0·77 g l−1 γ‐PGA in strain RSF‐EBCAE(BS). We also confirmed that the rate‐limiting genes of the γ‐PGA biosynthesis pathway were pgsB and pgsC.
Significance and Impact of the Study
This work is beneficial to increase γ‐PGA production and study the mechanism of γ‐PGA biosynthesis enzymes.
Abstract
Interest in the phenomenon of laser ablation (LA) has gained significant attention in recent years due to its potential for machining, high‐precision drilling, and cutting materials, such as ...metals, semiconductors, and dielectrics. Here, LA of ethylene‐butyl acrylate (EBA) filled with different volume fractions (4%, 8%, and 20%) of CB particles is studied. Upon irradiation with the second harmonics (532 nm) of the nanosecond pulsed Nd:YAG laser, a structuration is evidenced at the sample surface in a restricted range of fluence and at high pulse number (PN) (500 pulses, 1 Hz). The laser‐ablated surface is analyzed by microtopography, scanning electron microscopy (SEM), and x‐ray photoelectron spectroscopy (XPS). Collectively, our data show a lowering in ablation threshold and depth for CB volume fractions larger than the conduction threshold (8%), indicating that visible radiation primarily induces photothermal effects. After redeposition of the ablation products at the surface, XPS indicates that high CB content in the EBA matrix induces high oxidation level of the composite surface. Furthermore, our results reveal that LA produces a significant proportion of amorphous carbon. Several parameters which affect heat accumulation and CB particle shielding are discussed. Such parameters include laser fluence and repetition rate, and CB content.
Due to the limited temperature capability of current YSZ thermal barrier coating (TBC) material, considerable effort has been expended world-wide to research new candidates for TBC applications above ...1200 °C. Our study suggested that Sc2O3 and Y2O3 co-doped ZrO2 (ScYSZ) had excellent t’ phase stability even after annealed at 1500 °C for 336 h. The thermal expansion coefficient of ScYSZ was comparable to the value of YSZ. The thermal conductivity of fully dense ScYSZ was in the range of 2.13–1.91 W m−1 K−1 (25–1300 °C), approximately 25% lower than that of YSZ. Although the fracture toughness of dense ScYSZ was slightly lower than YSZ, an evident decline in elastic modulus was found. Additionally, thermal cycling lifetime of plasma sprayed ScYSZ coating (914 cycles) at 1300 °C was about 2.6 times longer than its YSZ counterpart. The superior comprehensive properties confirm that ScYSZ is a prospective candidate material for high-temperature TBC application.
Background
Conformal sphincter preservation operation (CSPO) is a new surgical procedure for very low rectal cancers (within 4–5 cm from the anal verge). CSPO preserves more of the dentate line and ...distal rectal wall and also avoids injuring nerves in the intersphincteric space, resulting in satisfactory anal function after resection. The aim of this study was to analyze the short-term surgical results and long-term oncological and functional outcomes of CSPO.
Methods
Consecutive patients with very low rectal cancer, who had CSPO between January 2011 and October 2018 at Changhai Hospital, Shanghai were included. Patient demographics, clinicopathological features, oncological outcomes and anal function were analyzed.
Results
A total of 102 patients (67 men) with a mean age of 56.9 ± 10.8 years were included. The median distance of the tumor from the anal verge was 3 (IQR, 3–4) cm. Thirty-five patients received neoadjuvant chemoradiation (nCRT). The median distal resection margin (DRM) was 0.5 (IQR, 0.3–0.8) cm. One patient had a positive DRM. All circumferential margins were negative. There was no perioperative mortality. The postoperative complication rate was 19.6%. The median duration of follow-up was 28 (IQR, 12–45.5) months. The local recurrence rate was 2% and distant metastasis rate was 10.8%. The 3-year overall survival and disease-free survival rates were 100% and 83.9%, respectively. The mean Wexner incontinence and low anterior resection syndrome scores 12 months after ileostomy reversal were 5.9 ± 4.3, and 29.2 ± 6.9, respectively.
Conclusions
For patients with very low rectal cancers, fecal continence can be preserved with CSPO without compromising oncological results.
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