Thick grain boundary induced strengthening in nanocrystalline Ni alloy

Grain refinement has been extensively used to strengthen metallic materials for decades. Grain boundaries act as effective barriers to the transmission of dislocations, consequently leading to strengthening. Conventional grain boundaries have a thickness of 1-2 atomic layers, typically ∼0.5 nm for most metallic materials. Here, we report, however, the formation of ∼3 nm thick grain boundaries in a nanocrystalline Ni alloy. In situ micropillar compression studies coupled with molecular dynamics simulations suggest that the thick grain boundaries are stronger barriers than conventional grain boundaries to the transmission of dislocations. This study provides a fresh perspective for the design of high strength, deformable nanostructured metallic materials.

Phosphorylation of nucleopolyhedrovirus 39K is essential for the regulation of viral gene transcription in silkworm cells

39K protein was proven to be the most notable hyperphosphorylated protein of Bombyx mori nucleopolyhedrovirus (BmNPV), since its amino acid 136 has the highest phosphorylation ratio (16.683) among all of BmNPV phosphorylated proteins (Shobahah et al., 2017). Therefore, we inserted positive (mimicking phosphorylation) and negative (mimicking dephosphorylation) mutants of the highest phosphorylated site of 39K and the wild type 39k into the 39k-ko-Bacmid using the Bac-to-Bac system. These three kinds of recombinant Bacmids along with wild type and knocked-out Bacmid were then transfected into the Bombyx mori cells (BmN) and further investigated by qPCR analysis. The results of the qPCR showed that 39K phosphorylation had no significant effect on viral genome replication, unlike the positive mutation that reduced the viral gene transcription drastically compared to the wild type. Thus, phosphorylation of BmNPV 39K protein does not appear to be the essential mechanism for viral genome replication, even though it has an important role in the viral gene transcription. Keywords: BmNPV; 39K; phosphorylation; virus replication; virus transcription.

Impacts of Various Dry-Aging Methods on Meat Quality and Palatability Attributes of Beef Loins from Cull Cow

ObjectivesBeef from cull cows has been traditionally perceived as low-quality/value meat due to its inferior flavor and tenderness. Given the negative consumer perception of highly processed fresh meat, there is a need to develop a natural post-harvest aging system to improve eating quality attributes of beef products, particularly from cull cows. Dry aging has been practiced for decades as a traditional and natural butchery process, which is also known to improve palatability characteristics. Thus, the main objective of this study was to evaluate the impact of different dry-aging methods on meat quality, microbiological properties and palatability attributes of loins from cull cow beef.Materials and MethodsPaired beef loins from 13 carcasses (Holstein, 30+ mo) were obtained at 5d postmortem, divided into 4 equal length sections and randomly assigned to four aging methods: wet-aging (WA), dry-aging (DA), dry-aging in water permeable bag (DWA) and UV-light dry-aging (UDA; 2 treatment/day, 5 J/s/treatment). Sections were aged for 28d at 2°C, 65% RH and 0.8 m/s air flow. After aging, dry-aged sections (DA, DWA and UDA) were trimmed of dehydrated surface, and trim loss and total saleable yield were recorded. The pH, proximate composition, shear force, water-holding capacity, initial color (instrumental and trained panelist), lipid oxidation (2-thiobabituric acid reactive substances, TBARS), microbial properties (aerobic plate count (APC), lactic acid bacteria (LAB), and yeast and mold (YM) counts) and trained sensory evaluation (11 panelists) were determined. Experimental design was a balanced complete block design. All data were analyzed using PROC MIXED procedure of SAS, and least squares means for all traits were separated (P < 0.05).ResultsDA and UDA had a substantial moisture loss during the aging process, accompanied with higher trim loss compared to other methods (P < 0.05). This resulted in DA having the lowest yield followed by UDA, DWA and WA with the highest saleable yield (P < 0.05). No significant differences were observed on cook loss, WBSF and TBARS between the treatments. DWA had the lowest pH out of all treatments (P < 0.05). UDA had the lowest moisture content and highest drip loss (P < 0.05). Color measurement showed that both DA and WA had significantly higher L* and lower b* values compared to UDA and DWA (P < 0.05). However, a* and lean surface color were not significantly different between the treatments (P > 0.05). For the trim, UDA had the lowest microbial growth among all treatments (P < 0.05). For the lean, UDA had the lowest count for LAB (P < 0.05), WA had the lowest in YM (P < 0.05) and no difference was found for APC between treatments (P > 0.05). Trained sensory panelist found that UDA and WA had higher fat and sour flavor (P < 0.05), and a trend (P = 0.07) of higher oxidized flavor when compared to DWA and DA.ConclusionThe results showed that dry-aging would result in no adverse impact on shear force, cooking loss, initial color and lipid oxidation of mature beef loins. Further, sour and oxidized flavor was lower in dry-aged beef, indicating its potential as value adding process. UV light application minimized microbial growth during dry-aging process, although more analyses are needed to understand its full impact on dry-aged meat quality. Further studies on determining the consumer acceptability as well as flavor-related compound analyses are currently under investigation.

Efficacy of Beef Crust from Dry-Aged Beef Loins as Novel Functional Ingredient

ObjectivesDry-aging is a traditional butchery process, but currently, it has been more practiced in a niche market as a value-adding process. As dry aging involves placing primal/sub-primal sections under a controlled refrigerated condition without packaging materials, the formation of the dried surface (crust) is inevitable due to moisture evaporation. A considerable portion of the crust is to be trimmed off as waste, which is one of the major drawbacks of dry aging. While the beef crust may still exert its functional/technological properties, no information is available regarding the efficacy of utilizing beef crust as a potential food ingredient. Thus, the objective of this study was to determine the physicochemical and functional properties of beef crust from dry-aged beef loins processed under various dry-aging conditions.Materials and MethodsPaired bone-in beef shell loins from 13 cull cow carcasses (C-maturity) were obtained at 5d postmortem, divided into 2 sections and assigned to four aging treatments: wet-aging (WA), dry-aging (DA), dry-aging in water-permeable bag (DWA) and dry-aging under UV-light (UDA; 5 J/s/12 h per day). Beef sections were aged for 28d at 2°C, 65% RH and 0.8 m/s air flow. After aging, the crusts were separated and beef samples from WA and initial (aged for 0 d, INI) were collected for comparison. In three independent batches, the crust samples were freeze-dried and powdered. Moisture contents of samples were measured before lyophilization. Emulsification capacity, salt-soluble protein solubility, emulsifying activity index, and surface hydrophobicity were determined. CIE* color attributes, lipid oxidation (TBARS), and protein oxidation (carbonyl and thiol contents) were measured. The PROC MIXED procedure of SAS was used to analyze the data. Significance level of least square means was set at the confidence level of 95%.ResultsBeef crusts from dry-aged loins had lower moisture contents compared with WA and INI (P < 0.05), while no difference between dry-aging methods was found (P > 0.05). The crust samples had lower L* and chroma values than WA and INI (P < 0.05). Emulsification capacity of DA, DWA, and UDA were lower than WA and INI (P < 0.05), with DA being the lowest (P < 0.05). In general, the crust had a significantly higher salt-soluble protein solubility compared to WA, while no difference between crusts and INI was found (P > 0.05). For emulsifying activity index, DA exhibited higher values than DWA, UDA and WA (P < 0.05), and was comparable to INI (P > 0.05). DA and INI had higher surface hydrophobicity values than the other samples, which could possibly explain the results of emulsifying activity index. A trend of higher TBARS values was found in all dry-aged crusts than WA and INI (P = 0.0688). The crust from dry aging had a higher carbonyl content compared to WA (P < 0.05), while thiol contents were not affected by the treatment (P = 0.1092).ConclusionThe results from the current study indicate that beef crusts exert its functional and technological properties, which could be superior or at least equivalent to wet-aged or unaged beef samples. This study provides novel insight into the potential feasibility and utilization of beef crust from dry-aged beef as a value-added product. Further studies determining the practical application of beef crust as a novel food ingredient (e.g., meat emulsion or beef patty) are in progress.

SENP3 protects H9C2 cells from apoptosis triggered by H/R via STAT3 pathway

OBJECTIVE

To investigate whether SENP3 protects H9C2 cells from apoptosis triggered by H/R through the signal transducer and activator of transcription 3 (STAT3) pathway.

MATERIALS AND METHODS

Male C57BL mice were cultured and mouse models of myocardial I/RI were established. At the same time, cardiomyoblast H9C2 cell line of rat embryo was cultured. Reactive oxygen species (ROS) level was detected during H/R using 2',7'-dichlorofluorescein diacetate (DCFH) kit. Apoptotic cells were checked by flow cytometry. The expressions of p-JAK2, JAK2, STAT3, p-STAT3, cleaved-caspase3 (c-caspase3), and Bcl/Bax were detected using Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

We revealed that SENP3 rose in mice of I/R group and in H9C2 cells following H/R with an increase in p-STAT3. Furthermore, increased expression of SENP3 was found to be dependent on the generation of ROS, as the SENP3 accumulation was inhibited by antioxidant (NAC). Inhibition of SENP3 suppressed the p-STAT3 expression, but promoted cell apoptosis, c-caspase3 expression, and Bcl/Bax ratio. Besides, SENP3 overexpression alleviated the cell apoptosis, which was abrogated by AG490.

CONCLUSIONS

SENP3 could protect H9C2 against H/R through enhancing JAK2/STAT3 pathway.

[Related factors on skip metastasis of neck lymph node in papillary thyroid carcinoma]

Objective: To investigate the correlation between skip metastasis of neck lymph node and clinicopathological features in papillary thyroid carcinoma. Methods: Totally 272 papillary thyroid carcinoma patients with lateral lymph node metastases who received surgical procedure at Department of Thyroid Surgery, the First Hospital of the Jilin University from January 2014 to June 2016 were analyzed retrospectively. There were 105 male and 167 female patients, aging from 16 to 73 years with a mean age of (42±8) years. There were 29 patients (10.7%) with skip metastasis. And then the correlation between skip metastasis of neck lymph node and clinicopathological features was analyzed by χ(2) test and multivariate Logistic regression test. Results: The rate of skip metastasis in all patients was 10.7% (29/272). By summarizing the distribution of the lateral lymph nodes about the patients with skip metastasis, 16 cases metastasized in single level (55.2%), meanwhile 6 in two levels (20.7%) and 7 in three levels (24.1%). Strong correlation between age, tumor location and skip metastasis was found using χ(2) test (χ(2) values were 14.056 and 21.362 respectively, both P values were 0.000). Age (>45 years) (OR=4.318, 95% CI: 1.767 to 10.552, P=0.001), microcarcinoma (OR=2.623, 95% CI: 1.013 to 6.795, P=0.047)and the tumor located in the upper of the thyroid (OR=11.982, 95% CI: 2.533 to 56.173, P=0.002) were risk factors to the skip metastasis through multivariable Logistic regression analysis. Conclusions: Age >45 years old, microcarcinoma or tumor located in the upper part of the thyroid gland was more likely present with skip metastasis. Skip metastases are often involved in the lateral multi-level. Therefore, confronted patients with one of these risk factors, the occurrence of skip metastasis should be awared when the lateral lymph node was large abnormally. Accordingly, it may be appropriate to extend the indications of fine needle aspiration for lateral lymph node in order to prevent missed diagnosis.

KR, Ziaee F, Xue S, Le AT, Ben-Itzhak I, Rolles D, Rudenko A. Time-resolved imaging of bound and dissociating nuclear wave packets in strong-field ionized iodomethane

We report the results of a time-resolved coincident ion momentum imaging experiment probing nuclear wave packet dynamics in the strong-field ionization and dissociation of iodomethane (CH₃I).

[Clinicopathological features of thyroid papillary microcarcinoma of which the maximum diameter is less than 5 mm: a series of 487 cases]

Objective: To analyze the clinical and pathological features of papillary thyroid microcarcinoma(PTMC) of which the maximum diameter is less than 5 mm. Methods: Clinical data of 487 PTMC (≤5 mm) patients who underwent primary surgery by the same team of doctors between March 2013 to March 2016 at Department of Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University were analyzed retrospectively. Female patients accounted for 77.4%(377/487). The age ranged from 22 to 80 years, with an average of (46±11) years.χ² test and multivariate Logistic regression analysis were used to analyze risk factors. Results: There were 93.6% (456/487) of the patients with preoperative definite diagnosis. There were 92.6% (452/487) of the patients underwent unilateral thyroid lobectomy with isthmectomy and ipsilateral central lymph node dissection. Multifocal carcinoma accounted for 20.3% (99/487), Ⅲ to Ⅳ phase cases accounted for 12.3% (60/487), patients with low risk of recurrence accounted for 67.6% (329/487). The central lymph node metastasis rate was 34.9% (170/487). Male (OR=2.149, 95%CI: 1.367 to 3.381), age<45 years (OR=0.451, 95%CI: 0.303 to 0.672), multifocal carcinoma (OR=1.798, 95%CI: 1.116 to 2.898), and capsular invasion (OR=3.678, 95%CI: 1.406 to 9.622) were the independent risk factors for lymph node metastasis (P<0.05). Conclusion: Regardless of tumor size, PTMC still needs to be taken seriously, especially male, age < 45 years, capsular invasion, or multifocal carcinoma patients.

In situ heavy ion irradiation studies of nanopore shrinkage and enhanced radiation tolerance of nanoporous Au

High energy particle radiations induce severe microstructural damage in metallic materials. Nanoporous materials with a giant surface-to-volume ratio may alleviate radiation damage in irradiated metallic materials as free surface are defect sinks. Here we show, by using in situ Kr ion irradiation in a transmission electron microscope at room temperature, that nanoporous Au indeed has significantly improved radiation tolerance comparing with coarse-grained, fully dense Au. In situ studies show that nanopores can absorb and eliminate a large number of radiation-induced defect clusters. Meanwhile, nanopores shrink (self-heal) during radiation, and their shrinkage rate is pore size dependent. Furthermore, the in situ studies show dose-rate-dependent diffusivity of defect clusters. This study sheds light on the design of radiation-tolerant nanoporous metallic materials for advanced nuclear reactor applications.

Protective effects of three remote ischemic conditioning procedures against renal ischemic/reperfusion injury in rat kidneys: a comparative study

BACKGROUND

Remote ischemic perconditioning (RIPerC), remote ischemic postconditioning (RIPostC), and remote ischemic perconditioning + postconditioning (RIPerC + RIPostC) protect against renal ischemia reperfusion injury (IRI). However, the most beneficial approach among these is not known.

AIMS

To compare the protective effects and study the mechanisms of three different remote ischemic conditioning in preventing IRI in the rat kidney.

METHODS

Fifty healthy adult male Sprague-Dawley rats were randomly assigned to five groups: sham, IRI, RIPerC, RIPostC, and RIPerC + RIPostC. Right nephrectomy was performed initially in all rats. IRI was induced by occluding the left renal artery for 60 min, followed by reperfusion for 24 h. RIPerC, RIPostC, and RIPerC + RIPostC were induced with 5-min ischemia/reperfusion (I/R) cycles using a tourniquet on the right hind limb.

RESULTS

The IRI group showed significant serologic evidence of renal injury compared to the sham group (P < 0.05). The RIPerC, RIPostC, and RIperC + RIpostC groups displayed significantly lower levels of renal dysfunction than the IRI group (P < 0.05). Superoxide dismutase (SOD) levels were significantly lower in the IRI group than in the sham group (P = 0.003), but were significantly less depressed in the RIPerC, RIPostC, and RIperC + RIpostC groups (P < 0.05). The IRI group displayed more severe renal tubular injury than the RIPerC, RIPostC, and RIPerC + RIPostC groups (P < 0.05).

CONCLUSION

All three remote ischemic conditioning showed similar therapeutic potential for preventing renal IRI. The RIPerC + RIPostC protocol did not show an additive effect from the combination of preconditioning and postconditioning. The protective mechanism may be due to the stimulation of endogenous antioxidant activity by transient limb ischemia-reperfusion.

Overexpression of the growth arrest-specific homeobox gene Gax inhibits proliferation, migration, cell cycle progression, and apoptosis in serum-induced vascular smooth muscle cells

The Gax gene has been implicated in a variety of cell-developmental and biological processes, and aberrant Gax expression is linked to many diseases. In this study, to provide important insights for Gax-based gene therapy in vein graft restenosis and its anti-restenotic mechanism, we used rabbit vascular smooth muscle cells (VSMCs) to investigate the effects of Gax overexpression on proliferation, migration, cell cycle, and apoptosis in a serum-stimulated culture. Rabbit VSMC lines that stably overexpressed Gax were established by transfection with recombinant adenoviral vector Ad5-Gax. The effect of Gax overexpression on in vitro serum-induced VSMCs proliferation, migration, cell cycle, and apoptosis was assessed by MTT, wound healing, and flow cytometry assays, respectively. To investigate the effect of Gax overexpression on PCNA and MMP-2 in serum-induced VSMCs, immunocytochemistry, RT-PCR, and gelatin zymography were performed. The results clearly showed that Gax overexpression decreases PCNA expression in serum-induced VSMCs. Gax overexpression also significantly inhibited cell proliferation by blocking entry into the S-phase of the cell cycle, promoted cell apoptosis, and reduced cell migration activity by downregulating MMP-2 release and activity. These findings indicate that Gax would be an optimal target gene for gene therapy to treat vein graft restenosis.

Free iliac flap for treating multiple skin defects of the hand and digits

A total of eight cases with multiple skin defects of the hand and digits were resurfaced using a free iliac flap. The lesions involved both the hand and multiple digits in five patients and multiple digits in three patients. The average skin flap size was 89.3 cm(2). In three, a piece of of vascularized iliac bone was included. There was no flap loss. Flap debulking was performed in five patients at 10-12 weeks post-surgery during the operation for flap separation and inset. Secondary flap debulking was performed in one patient at 6 months post-surgery. The average static 2-point discrimination was 15.4 mm in five patients, whereas the remaining patients only exhibited sensation to pressure. This procedure may require additional refinement; however, the free iliac flap with technical refinements is a viable option for the treatment of multiple skin defects of the hand and digits.

Comparison of the safety and efficacy of conventional monopolar and 2-micron laser transurethral resection in the management of multiple nonmuscle-invasive bladder cancer

Objectives

To compare the safety and efficacy of conventional monopolar transurethral resection of bladder tumour (TURBT) and 2-micron continuous-wave laser resection (2-µm laser) techniques in the management of multiple nonmuscle-invasive bladder cancer (NMIBC), and to investigate long-term effects on tumour recurrence.

Methods

Patients with multiple NMIBC were randomized to receive TURBT or 2-µm laser in a nonblinded manner. All patients received intravesical chemotherapy with epirubicin (40 mg/40 ml) for 8 weeks, beginning 1 week after surgery, followed with monthly maintenance therapy for 12 months. Three-year follow-up data of preoperative, operative and postoperative management were recorded.

Results

In total, 120 patients were included: 56 in the TURBT group and 64 in the 2-µm laser group. Intra- and postoperative complications (including bladder perforation, bleeding and irritation) were less frequently observed in the 2-µm laser group compared with the TURBT group. There were no significant differences in first time to recurrence, overall recurrence or occurrence of urethral strictures.

Conclusions

The 2-µm laser resection method was more effective than TURBT in reducing rates of intra- and postoperative complications, but offered no additional benefit regarding tumour recurrence.

Changes in quantity and spectroscopic properties of water-extractable organic matter during soil aquifer treatment

The aim of this study was to identify qualitative and quantitative changes in the character of water-extractable organic matter (WEOM) in soils as a consequence of soil aquifer treatment (SAT). Soil samples were obtained from a soil-column system with a 2-year operation, and divided into seven layers from top to bottom: CS1 (0-12.5 cm), CS2 (12.5-25 cm), CS3 (25-50 cm), CS4 (50-75 cm), CS5 (75-100 cm), CS6 (100-125 cm) and CS7 (125-150 cm). A sample of the original soil used to pack the columns was also analysed to determine the effects of SAT. Following 2 years of SAT operation, both soil organic carbon and water-extractable organic carbon were shown to accumulate in the top soil layer (0-12.5 cm), and to decrease in soil layers deeper than 12.5 cm. The WEOM in the top soil layer was characterized by low aromaticity index (AI), low emission humification index (HIX) and low fluorescence efficiency index (F(eff)). On the other hand, the WEOM in soil layers deeper than 12.5 cm had increased values of HIX and F(eff), as well as decreased AI values relative to the original soil before SAT. In all soil layers, the percentage of hydrophobic and transphilic fractions decreased, while that of the hydrophilic fraction increased, as a result of SAT. The production of the amide-2 functional groups was observed in the top soil layer. SAT operation also led to the enrichment of hydrocarbon and amide-1 functional groups, as well as the depletion of oxygen-containing functional groups in soil layers deeper than 12.5 cm.