First-in-man study of Heartech® percutaneous left ventricular partitioning device for treatment of heart failure postmyocardial infarction

OBJECTIVE

This first-in-man (FIM) study aimed to determine the safety and efficacy of the Heartech® left ventricular partitioning device (LVPD) in patients with chronic heart failure (HF) postmyocardial infarction.

METHODS

Sixteen patients were enrolled from three cardiac intervention centers in China. All patients underwent percutaneous ventricular restoration (PVR) procedures with implantation of the Heartech® LVPD. Safety and immediate success rates were recorded. Major adverse cardiovascular and cerebrovascular events (MACCEs) including all-cause mortality, myocardial infarction, stroke, emergent or selective surgery or interventional therapy, renal failure requiring hemodialysis, and major bleeding were recorded. Efficacy features included functional status, echocardiographic characteristics, life quality characteristics including peak oxygen consumption of cardiopulmonary exercise testing (CPET), European five-dimensional health scale (EQ-5D), 6-min walk test (6MWT) at baseline and during follow-up (NCT02938637).

RESULTS

The device success rate was 93.75% (15 successes in 16 patients) with 100% safety. During follow-up of 36 ± 4.5 days, no MACCEs were found. The left ventricular end-systolic volume index decreased significantly (LVESVi, 72.47 ± 22.77 mL/m² vs. 50.13 ± 13.36 mL/m² , p < .001) as did left ventricular end diastolic volume index (LVEDVi, 106.27 ± 28.01 mL/m² vs. 83.20 ± 16.87 mL/m² , p = .001). Left ventricular ejection fraction (LVEF, 32.47 ± 6.98% vs. 40.41 ± 6.15, p < .001), 6MWT (383.13 ± 108.70 vs. 453.47 ± 88.24, p < 0.001) and EQ-5D (65.93 ± 11.25 vs. 78.67 ± 8.35, p < .001) improved significantly.

CONCLUSIONS

Heartech® LVPD appeared to be safe and effective for treatment of HF postmyocardial infarction.

MiR-181a affects myocardial ischemia-reperfusion injury in rats via regulating akt signaling pathway

OBJECTIVE

The aim of this study was to explore the influence of the micro ribonucleic acid (miR)-181a on myocardial ischemia-reperfusion injury (MIRI) in rats by regulating the protein kinase B (Akt) signaling pathway.

MATERIALS AND METHODS

A total of 30 male Sprague-Dawley rats were randomly divided into three groups, including: sham operation group (Sham group), ischemia-reperfusion group (I/R group), and miR group (MiR-181a group). The model of myocardial ischemia-reperfusion was successfully established in rats. The concentration of blood nitric oxide (NO) was detected by the relative kits. Myocardial apoptosis in rats of the three groups was detected using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Furthermore, the expressions of myocardial cell apoptosis-related proteins and tumor necrosis factor-α (TNF-α), and the degree of Akt phosphorylation were determined by Western blotting.

RESULTS

Compared with Sham group and miR-181a group, I/R group exhibited significantly elevated left ventricular end-diastolic pressure (LVEDP) (p<0.05). However, the left ventricular end-systolic pressure (LVESP), stroke work (SW), differential pressure (DP), end-systolic pressure-volume relationship (ESPVR), and end-diastolic pressure-volume relationship (EDPVR) significantly decreased in the I/R group (p<0.05). In comparison with miR-181a group, the apoptosis index of myocardial cells was remarkably elevated in the I/R group, showing statistically significant differences (p<0.05). The protein bands were analyzed using the Quantity One detection software. The results demonstrated that, compared with the Sham group, I/R group showed significantly elevated expressions of cysteine-aspartic protease (Caspase)-3 and TNF-α in rat myocardial tissues (p<0.05). However, the protein levels of Akt and endothelial NO synthase (eNOS) phosphorylation and NO in rat myocardial cells were significantly down-regulated (p<0.05).

CONCLUSIONS

MiR-181a activates Akt to promote the phosphorylation of its downstream protein eNOS, inhibit the apoptosis of myocardial cells, and alleviate MIRI.

[Surveillance and sociological factors of schistosomiasis among mobile populations in Haining City]

OBJECTIVE

To investigate the correlation between the source of Schistosoma japonicum infections and sociological factors among mobile populations in Haining City, so as to provide insights into the management of schistosomiasis among mobile populations in Haining City.

METHODS

A total of 12 villages were randomly sampled from 8 townships and 4 subdistricts in Haining City. The mobile populations from schistosomiasis-endemic areas were detected for S. japonicum infections using serological tests. In addition, the awareness of schistosomiasis prevention and control knowledge was investigated using a questionnaire survey.

RESULTS

A total of 1 019 mobile populations were investigated in 12 villages from Haining City, and 23 sero-positives were found, with a positive rate of 2.26%; however, no egg-positives were detected. Logistic regression analysis showed that the mobile populations with original occupations of aquaculture and husbandry were more likely to be sero-positive. The mobile populations had an overall low awareness rate of schistosomiasis prevention and control knowledge, and a higher rate was seen in sero-positive than in sero-negatives.

CONCLUSIONS

The mobile populations with original occupations of aquaculture and husbandry were the key for the surveillance of source of S. japonicum infections. The health education should be intensified to improve the awareness of schistosomiasis prevention and control knowledge among mobile populations.

Optimization of Dietary Zinc Requirement for Broiler Breeder Hens of Chinese Yellow-Feathered Chicken

Simple Summary

China is the second-largest global producer of chicken meat, almost half of which is from the Chinese yellow-feathered breed; a systematic program has been initiated to improve its feeding standards. This study evaluated the optimal requirement of dietary zinc for maximal egg production, egg quality, tibial quality, and antioxidant indices of laying broiler breeders. The results revealed several beneficial effects of supplementary zinc on egg production, feed conversion ratio, yolk zinc content, tibial quality and the antioxidant indices in the serum, liver and ovary. The optimal zinc requirement was estimated based on a regression model.

Abstract

This study aimed to establish the optimal dietary zinc requirement of Chinese yellow-feathered Lingnan broiler breeders. A total of 576 breeder hens aged 58 weeks were randomly assigned to six treatments, each with 6 replicates of 16 birds (n = 96/treatment). The hens were fed either a basal diet (22.81 mg/kg Zn) or the same basal diet supplemented with additional 24, 48, 72, 96, and 120 mg Zn/kg up to 65 weeks of age. Compared to the results of birds fed the basal diet (22.81 mg Zn/kg), the dietary supplementation with additional Zn (mg/kg) showed higher egg laying rate (at 48–120 mg), EM (at 96 mg/kg), yolk Zn content (at 24–120 mg/kg), fertility (at 48–120 mg/kg), hatchability (at 48–96 mg/kg), tibial breaking strength (at 24–48 mg/kg), tibial ash content (at 48 mg/kg), serum CuZnSOD activity (at 72 mg/kg) and T-AOC (at 48 mg/kg), and ovarian CuZnSOD and GSH-Px activities (at 96–120 mg/kg), and lower FCR (at 96 mg/kg). The regression model showed that the optimal supplemental Zn for maximal egg laying rate, yolk Zn content, fertility, and hatchability of Chinese yellow-feathered broiler breeders aged 58 to 65 weeks were 71.09, 92.34, 94.44 and 98.65 mg/kg diet, respectively.

Effect of exogenous ammonium gluconate on growth, ion flux and antioxidant enzymes of maize (Zea Mays L.) seedlings under NaCl stress

Ammonium gluconate (AG) provides both an organic carbon source and a nitrogen source, which can positively improve soil fertility and delay soil degradation. We investigated the underlying mechanisms of both NH₄ ⁺ - and C₆ H₁₁ O₇ ^- -mediated resistance to high salt concentrations in maize (Zea mays L.), and how they relate to antioxidant cellular machinery, root system architecture, root activity and lignin content in roots. Seedlings treated with AG maintained lower Na⁺ content, higher chlorophyll content, higher CAT and POD activity, compared with those without AG and ammonium carbonate (AC). The total size of the root system, primary root length and number of lateral roots detected on the primary root treated with AG decreased compared with those not treated with AG at the same NaCl concentration. However, average root diameter and root activity when treated with AG were significantly higher than roots without AG at the same NaCl concentration. Furthermore, total size of the root system, primary root length and number of lateral roots detected on primary rootsof seedlings treated with AG were higher than those treated with AC at the same NaCl concentration. These results suggested that AG may be a good organic fertiliser under salt stress by decreasing Na⁺ content and increasing chlorophyll content, activity of antioxidant enzymes, root diameter and root activity in maize seedlings.

RNA interference-mediated silencing of aquaporin (AQP)-5 hinders angiogenesis of colorectal tumor by suppressing the production of vascular endothelial growth factor

Aquaporin (AQP)-5 is an essential member of AQP family involved in the tumorigenesis of various malignant tumors. However, its role in the angiogenesis of colorectal cancer is unclear and requires further investigation. In this study, a pRNA-H1.1 vector containing the short hairpin RNA (shRNA) targeting AQP5 mRNA was constructed to inhibit the endogenous expression of AQP5 in human umbilical vein endothelial cells (HUVECs). We found that the AQP5-silenced HUVECs acquired decreased proliferation, migration and tube formation ability. AQP5 shRNA also inhibited the enzyme activity of matrix metalloprotease (MMP)-9 in HUVECs without affecting the MMP-2. Further, two colorectal cancer cell lines (HT29 and HCT116) stably transfected with scrambled or AQP5 shRNA were established. The expression and secretion of vascular endothelial growth factor (VEGF)-A (a pro-angiogenic factor) in colorectal cancer cells were downregulated by AQP5 shRNA. HUVECs cultured in low-VEGF conditioned media (CM) obtained from cancer cells developed less vessel-like tubes and had decreased proliferation and migration. The growth and angiogenesis of xenograft tumors were suppressed when the endogenous AQP5 in HT29 cells was knocked down. Tumor samples were additionally collected from patients with colorectal cancer to analyze the expression of AQP5. The immunofluorescence data indicated that AQP5 was expressed in both inner cancer areas and CD31-positive vessels. Taken together, our study suggests AQP5 as a novel anti-angiogenesis target for colorectal cancer.

Therapeutic effects of probiotic Clostridium butyricum WZ001 on bacterial vaginosis in mice

AIMS

To observe the therapeutic effects of vaginal infusion of probiotic Clostridium butyricum WZ001 on bacterial vaginosis (BV) in mice.

METHODS AND RESULTS

Female ICR mice were used to establish the model of BV by infecting oestrogen-treated mice with Escherichia coli, and then treated with high- and low dose of C. butyricum. Clinical indexes of mice in the C. butyricum-treated groups were significantly improved and comparable to those in the antibiotic group. Pap staining showed that neutrophil count was significantly increased after modelling and largely decreased after C. butyricum treatment (P < 0·01). Dynamic observation of E. coli and Lactobacillus showed that the number of E. coli significantly decreased in the C. butyricum-treated groups or in the antibiotic group with prolonged treatment (P < 0·01). Besides, the number of E. coli in the low-dose C. butyricum group was higher than that in either its high-dose counterpart or the antibiotic group respectively (P < 0·01). The number of Lactobacillus decreased evidently in the antibiotic group (P < 0·01), while that in the C. butyricum groups remained consistent. Moreover, C. butyricum inhibited the proliferation of E. coli by the experiment in vitro. The phosphorylation of nuclear factor-kappa B (NF-κB) p65 in vaginal tissue and the serum levels of inflammatory cytokines, IL-1β, TNF-α and IL-6, increased after modelling and significantly decreased after treated with C. butyricum (P < 0·01), with no difference found when compared with the antibiotic group.

CONCLUSION

Clostridium butyricum inhibits the growth of pathogenic bacteria as well as the inflammatory response induced by E. coli and promotes the growth of Lactobacillus to maintain the vaginal micro-ecological balance.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results suggest that probiobitc C. butyricum WZ001 has a great potential in the clinical treatment of BV.

[Correlation between serum HBV DNA level and HBsAg titer in HBeAg-positive pregnant women and impact of genomic variability of hepatitis B virus pre S/S regions on their correlations]

Objective: To analyze the correlation between serum HBV DNA level and HBsAg titer in hepatitis B e antigen positive pregnant women without antiviral therapy, and investigate the impact of genomic variability of preS/S regions on their correlations. Methods: Prenatal serum samples from 882 pregnant women with chronic HBV infection who were positive for HBsAg, HBeAg and HBV DNA and were not on antiviral therapy were included in the analysis. The Abbott i2000 and m2000 systems were used to qualitatively or quantitatively detect HBsAg, HBeAg and HBV DNA levels, respectively. HBV genotyping was performed using a type-specific primer nested polymerase chain reaction (nPCR). In addition, serum samples of pregnant women with HBV DNA levels correlated with HBsAg titer and HBV DNA levels higher than HBsAg titers were used to perform preS/S region amplification by nPCR method. PCR products were directly sequenced and mutation sites were analyzed by MEGA6.0 stasticial software. Mann-Whitney U test was used for the measurement data, and 2-test test for count data. Correlations between variables were analyzed using Spearman's rank correlation. Results: Serum HBsAg titer of HBeAg-positive pregnant women was positively correlated with HBV DNA level (r = 0.754, P < 0.01). Compared with the control group, mutation sites A60V (100% vs. 15.38%, χ(2) = 7.61, P < 0.01), V90A (100% vs. 30.77%, χ(2) = 4.43, P < 0.05) and I161T of HBV preS/S region (80.00% vs. 0, χ(2) = 9.14, P < 0.01) showed a significant decrease in HBsAg titer. Conclusion: Serum HBV DNA levels were positively correlated with HBsAg titer in HBeAg-positive pregnant women. Therefore, serum HBsAg titer may be used as a surrogate marker of serum HBV DNA. Single or multiple amino acid mutations sites A60V, V90A, and I161T in preS/S region may be one of the reasons that lead to a significant drop in HBsAg titer and affect its correlation with HBV DNA levels.

[Liver transplantation for polycystic liver disease: 11 cases report and literature review]

Objective: To explore the indications and safety of orthopedic liver transplantation for polycystic liver disease (PLD). Methods: Data of 11 patients with PLD who underwent orthotopic liver transplantation between 2004 and 2013 was retrospectively analyzed. Demographic, clinical and follow-up data were collected for statistical analysis. The survival rate was calculated by Kaplan-Meier method. Results: Over a period of 10 years, the patients received modified piggyback orthopedic liver transplantation (n=9) or combined liver-kidney transplantation (n=2) for PLD. The recipients' median age was 56 years. Seven patients were classified as Gigot type Ⅱ PLD, and four were classified as Gigot type Ⅲ PLD. Eight patients had severe decreased mobility (Eastern Cooperative Oncology Group, ECOG≥3). Only three cases were Child-Pguh Class C patients and the model for end-stage liver disease (MELD) score was>20. The mean hospitalization duration was (45.4±15.3) days, and the mean length of stay in intensive care unit was (4.1±1.9) days. The perioperative mortality was 18.2% and morbidity of complications was 63.6%. The median follow-up period was 111 months. Two patients died of severe complications after combined liver-kidney transplantation. One patient died of ischemia cholangitis during follow-up. The actuarial 1-, 5-and 10-year survival rate during the follow-up period was 82.2%, 81.8%, and 65.5%, respectively. Conclusions: Liver transplantation is the only curative and safe procedure for PLD, and it provides a good long-term prognosis and high quality of life for PLD patients. Liver transplantation could be a primary option in treating progressive or advanced PLD.

Abstract P2-09-14: Immunogenomic pathway and survival analysis in breast cancers based on tumor location and molecular subtypes

Introduction: Most breast tumors respond poorly to immunotherapy. Triple-negative breast cancer (TNBC) breast tumors are thought to be more immunogenic than other breast cancer subtypes (luminal A/B or HER2+). Increased immune response in TNBC are characterized by high levels of tumor infiltrating T lymphocyte (TIL) composition that would predict excellent response to immune checkpoint blockade. For all breast cancers, tumors appear more commonly in the upper outer quadrant. However, it is not clear whether expression of immune response genes vary with tumor location among the subtypes. Here, we hypothesized that by analyzing differential gene expression associated with immune response pathways among molecular subtypes of breast cancer such as luminal A/B, HER2+ or TNBC, we can identify targetable pathways to improve therapy with breast cancer.

Methods: Using the Cancer Genome Atlas (TCGA) dataset, we have identified 918 breast cancer tumor samples and compared RNAseq gene expression based on molecular subtypes and anatomic locations of biopsies (i.e., right, left, lower inner quadrant, lower outer quadrant, upper inner quadrant or upper outer quadrant). Genes with significantly different expression (p&lt;0.01) were selected for survival analysis. R, Reactome Pathway Browser were used to retrieve and analyze data.

Results: In TNBC, tumors from lower outer quadrant, lower inner quadrant demonstrated significantly higher CD8B mRNA expression compared with luminalA/B and HER2 (p=2.93E-04, 2.73E-04) from same locations. CD8B mRNA was not significantly higher in TNBC tumors of other sites compared with luminalA/B and HER2. However, pathway/genes associated with CTL function remained significantly different between the different sites for TNBC compared with other subtypes. The metastasis suppressor gene, CD82, was significantly higher in TNBC samples from the right side (p=4.83E-05), lower outer quadrant (p=4.33E-05), lower inner quadrant (p=3.32E-03) and upper inner quadrant (p=4.51E-07), but this gene was not significantly expressed in the upper outer region, where tumors are prevalent.

From immune pathway analysis, genes involved in the antigen activates B cell receptor pathway (p&lt;0.05) were associated with overall survival (OS) in right and left sided Luminal A/B and HER2 tumors and right sided TNBC tumors. Finally, genes from pathway involved in immune-regulatory interactions between a lymphoid and a non-lymphoid cells were associated with OS in lower outer quadrant, upper outer quadrant tumors in luminal A/B and HER2 cases and right sided tumors in TNBC (p&lt;0.05).

Conclusion: While previous studies have reported that tumor infiltrating lymphocytes and lymphoid aggregates in tumors are associated with survival, following more complex analysis, we reveal novel genes and immune pathways that demonstrate improved survival prediction in the TCGA dataset for breast cancers. Furthermore, as expected, we confirm that different immune pathways are associated with survival in luminalA/B, HER2 and TNBC tumors. Our findings demonstrate the importance of a patient-centered approach to the treatment of patients with breast cancer.

Citation Format: Shen Y, Shyu C-R, Mitchem JB, Ding F, Shajahan-Haq AN. Immunogenomic pathway and survival analysis in breast cancers based on tumor location and molecular subtypes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-09-14.

[Quantitative evaluation of intravoxel incoherent motion diffusion-weighted imaging and three-dimensional arterial spin labeling in Ki-67 labeling index and grading of brain gliomas]

Objective: To investigate the value of multiple parameters derived from intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and three-dimensional arterial spin labeling (3D-ASL) in Ki-67 labeling index (Ki-67 LI) and grading of human brain gliomas. Methods: From December 2015 to May 2018, 45 patients of gliomas confirmed by surgical pathology in Li Huili Hospital, Ningbo Medical Center were divided into low-grade group (20 cases of WHO grade Ⅱ) and high-grade group (12 cases of WHO grade Ⅲ, 13 cases of WHO grade Ⅳ), and the Ki-67 LI of glioma was obtained by immunohistochemistry. All patients, 24 males and 21 females, aged 25-83 years, mean(53±12)years, underwent conventional magnetic resonance imaging (MRI), IVIM-DWI and 3D-ASL before operation, then measured the true water diffusion coefficient (D), microcirculation perfusion coefficient (D(*)), perfusion fraction (f) and cerebral blood flow (CBF) in the tumor solid area and the contralateral normal white matter area. Those parameters and the Ki-67 LI were compared between the low-and high-grade groups with Mann-Whitney U test. Spearman's correlation was used to analyze the correlation between the quantitative parameters and Ki-67 LI. The ROC curve was used to assess the diagnostic efficacy of parameters in the grading assessment of brain gliomas. Results: The D(0.791×10(-3)mm(2)/s) and f (0.261) of the high-grade group were lower than those of the low-grade group, whereas D(*) (4.153×10(-3) mm(2)/s), CBF(102.027 ml·min(-1)·100 g(-1)) and Ki-67 LI (0.25) were higher (P<0.05). There was a moderate negative correlation between D, f and Ki-67 LI(r=-0.513,-0.457, all P<0.05). There was no significant correlation between D(*) and Ki-67 LI (P=0.571). The area under the curve (AUC) for identifying high-and low-grade gliomas by D, D(*), f and CBF values was 0.965, 0.745, 0.842, and 0.830 respectively (all P<0.05). Conclusion: D and f can be used for quantitative prediction of Ki-67 LI. IVIM-DWI and 3D-ASL are helpful in the grading assessment of gliomas, and the diagnostic efficiency of D is the highest.

Development of classification models for predicting chronic toxicity of chemicals to Daphnia magna and Pseudokirchneriella subcapitata

Both the acute toxicity and chronic toxicity data on aquatic organisms are indispensable parameters in the ecological risk assessment priority chemical screening process (e.g. persistent, bioaccumulative and toxic chemicals). However, most of the present modelling actions are focused on developing predictive models for the acute toxicity of chemicals to aquatic organisms. As regards chronic aquatic toxicity, considerable work is needed. The major objective of the present study was to construct in silico models for predicting chronic toxicity data for Daphnia magna and Pseudokirchneriella subcapitata. In the modelling, a set of chronic toxicity data was collected for D. magna (21 days no observed effect concentration (NOEC)) and P. subcapitata (72 h NOEC), respectively. Then, binary classification models were developed for D. magna and P. subcapitata by employing the k-nearest neighbour method (k-NN). The model assessment results indicated that the obtained optimum models had high accuracy, sensitivity and specificity. The model application domain was characterized by the Euclidean distance-based method. In the future, the data gap for other chemicals within the application domain on their chronic toxicity for D. magna and P. subcapitata could be filled using the models developed here.

[Influence of UCHL5 on proliferation and apoptosis of SW527 breast cancer cells]

Objective: To investigate the effect of UCHL5 on proliferation and apoptosis of breast cancer cells. Methods: SW527 cells were infected with lentiviral vector carrying short hairpin RNA to delete the expression of UCHL5. 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was used to examine cell proliferation, and subcutaneous transplantation experiments were performed to detect tumor growth. Cell apoptosis was detected using Annexin V/ Propidium iodide (PI) double staining. The correlation between UCHL5 expression and the expressions of proliferation and apoptosis associated genes was analyzed using TCGA breast invasive carcinoma data set. The relationship between UCHL5 expression and breast cancer patients'survival was analyzed using Kaplan-Meier Plotter online tool. Results: After knockdown of UCHL5, A values of SW527 cells on day 2 and day 4 were 0.822±0.017 and 1.045±0.023, respectively, which were significantly lower than 0.976±0.016 and 1.284±0.025 of control cells on day 2 and day 4 (P<0.001). In vivo xenografted mouse model, the volume in UCHL5-suppressed group was (166.90±75.05) mm(3,) significantly smaller than (329.80±35.84) mm(3) in control group (P=0.029). Flow cytometry analysis showed the apoptotic rate of SW527 cells was (8.60±1.13)% after knockdown of UCHL5, significantly higher than (2.95±0.07)% of control group (P=0.020). TCGA database analysis showed that the expression of UCHL5 was positively correlated with the expressions of genes related to cell proliferation, in paralled with the increased expression of UCHL5, the expression of the pro-apoptosis associated genes was decreased. Kaplan-Meier Plotter analysis demonstrated that the overall survival and relapse-free survival of breast cancer patients with high expression of UCHL5 were much shorter (all P<0.001). Conclusions: Down-regulation of UCHL5 inhibits the proliferation and tumor formation and promotes apoptosis of SW527 cells. High expression of UCHL5 may predict poor prognosis of breast cancer patients.

Erratum: Observation of D^{0} Meson Nuclear Modifications in Au+Au Collisions at sqrt[s_{NN}]=200 GeV [Phys. Rev. Lett. 113, 142301 (2014)]

This corrects the article DOI: 10.1103/PhysRevLett.113.142301.

Why Some Noncentrosymmetric Borates Do Not Make Good Nonlinear Optical Materials: A Case Study with K3B5O8(OH)2

Synthesis of deep-ultraviolet (DUV) transparent materials, especially those with noncentrosymmetric structures, remains a great challenge in the solid-state chemistry community. A new DUV transparent borate, K₃B₅O₈(OH)₂, was discovered with a short absorption edge below 200 nm. The title compound crystallizes in a noncentrosymmetric, polar space group, Fdd2 (point group mm2), with the following cell parameters: a = 13.736(9) Å, b = 19.317(12) Å, c = 7.606(5) Å. The structure of K₃B₅O₈(OH)₂ features a 3D framework composed of [B₅O₈(OH)₂]^3- basic building units that are linked by contacts with K⁺ cations and O-H···O hydrogen bonds. Second harmonic generation (SHG) measurements were performed, and an SHG efficiency of 0.5 × SiO₂ was observed. Symmetry dictates that the χ₁₄ component of the macroscopic NLO susceptibility is equal to zero in mm2, which prevents the maximal component of the microscopic NLO susceptibility for [B₅O₈(OH)₂]^3- units (χ₁₄) from contributing to the macroscopic NLO susceptibility of the crystal and therefore limits the SHG efficiency. In contrast, large SHG effects can be observed from compounds containing [B₅O₁₀] units that crystallize in point groups with nonzero χ₁₄, such as 222. These findings provide insight into understanding the relationship between crystal structure and SHG efficiency in [B₅O₁₀]-based compounds and discovering other borate-based DUV materials.

Anomalous twin boundaries in two dimensional materials

Twin boundary defects form in virtually all crystalline materials as part of their response to applied deformation or thermal stress. For nearly six decades, graphite has been used as a textbook example of twinning with illustrations showing atomically sharp interfaces between parent and twin. Using state-of-the-art high-resolution annular dark-field scanning transmission electron microscopy, we have captured atomic resolution images of graphitic twin boundaries and find that these interfaces are far more complex than previously supposed. Density functional theory calculations confirm that the presence of van der Waals bonding eliminates the requirement for an atomically sharp interface, resulting in long-range bending across multiple unit cells. We show these remarkable structures are common to other van der Waals materials, leading to extraordinary microstructures, Raman-active stacking faults, and sub-surface exfoliation within bulk crystals.

All materials subjected to mechanical deformation form low energy interfaces known as twin boundaries. Here, the authors investigate a variety of structural features that form upon bending atomically thin 2D-crystals, and predict distinct classes of post deformation microstructure based on their atomic arrangement, bend angle and flake thickness.

Biomass decaying and elemental release of aquatic macrophyte detritus in waterways of the Indian River Lagoon basin, South Florida, USA

Decaying experiments of four major aquatic macrophyte detritus, namely cattail (Typha orientalis), water lettuce (Pistia stratiotes), hydrilla (Hydrilla verticillata) and maidencane (Panicum hemitomon), were conducted using the litterbag technique in the stormwater detention pond of South Florida, USA. Dry weight and chemical composition of remaining biomass were dynamically determined during the 185-day decay experiment. The results showed that decomposition rates (k), and the derived turnover (t_50% and t_95%) were species specific. The k values decreased in the order of hydrilla (0.0123 g day^-1) > water lettuce (0.0082 g day^-1) > maidencane (0.0049 g day^-1) > cattail (0.0031 g day^-1), whereas t_50% and t_95% varied in the reverse way. Biomass properties including concentrations of C, N, P, lignin, cellulose, hemicellulose, and the ratios of C/N, C/P, N/P and lignin/N affected decaying rate of the studied aquatic plants. The dry mass loss and concentrations of C, N, P, lead (Pb), chromium (Cr), copper (Cu), manganese (Mn), zinc (Zn), lignin, cellulose, hemicellulose and ratios C/N, C/P, N/P and Lignin/N of plant detritus were significantly affected by species, decaying time, and their interactions. However, the influence of species differences was greater than that of decaying time on those indexes. The estimated amounts (kg) of nutrients and metals released based on k values for the waterways of the IRL basin (water surface area 15.6 km²) were N 126.85 × 10³, P 8.89 × 10³, Zn 408.20, Pb 97.95, Cr 128.99, Mn 313.03, and Cu 82.40. Water lettuce contributed most, accounting for 52.13% N, 56.81% P, 74.95% Zn, 59.58% Pb, and 74.65% Mn, followed by hydrilla, cattail and maidencane. For Cr and Cu, cattail had the greatest contribution of 65.77% and 54.15%, respectively, followed by water lettuce, hydrilla and maidencane.

Syntheses, Structures, and Properties of Non-Centrosymmetric Quaternary Tellurates Bi MTeO6 ( M = Al, Ga)

Single crystals of two new metal tellurates Bi MTeO₆ ( M = Al, Ga) with a honeycomb layered structure were obtained by the molten flux method and characterized. The Bi MTeO₆ compounds both crystallize into a non-centrosymmetric trigonal space group of P312 (no. 149) with cell parameters of a = 5.0667(8) Å, c = 4.9920(16) Å and a = 5.107(3) Å, c = 4.932(6) Å, respectively. The non-centrosymmetry of BiAlTeO₆ and BiGaTeO₆ originates from the packing order of the octahedra. In these two structures, TeO₆ octahedra and MO₆ octahedra share edges and form a honeycomb open-framework with [Te MO₆]_∞ layers. The layers of [ MTeO₆]_∞ and [BiO₆]_∞ alternate and are connected along the c-axis by corner-sharing oxygen atoms to form the three-dimensional framework. The chiral compound BiGaTeO₆ exhibits a powder second harmonic generation (SHG) response of ∼0.2 times that of potassium dihydrogen phosphate (KDP) and an absorption edge of 355 nm.

Postcontrast T1 Mapping for Differential Diagnosis of Recurrence and Radionecrosis after Gamma Knife Radiosurgery for Brain Metastasis

BACKGROUND AND PURPOSE

The differential diagnosis of radionecrosis and tumor recurrence in brain metastases is challenging. We investigated the diagnostic efficiency of postcontrast T1 mapping in solving this problem.

MATERIALS AND METHODS

Between March 2016 and June 2017, fifty-six patients with brain metastases who underwent contrast-enhanced cerebral T1 mapping were recruited for this prospective study. The findings revealed new enhancement after gamma knife radiosurgery. The subjects were assigned to radionecrosis and recurrence groups based on follow-up (median, 11.5 months) and histopathologic results. T1 values of lesions 5 (T1_5min) and 60 (T1_60min) minutes after administration of contrast agent and their difference (T1_differ) were compared between the 2 groups with the 2-tailed Mann-Whitney U test. Receiver operating characteristic curves were used to determine the optimum cutoff values for differential diagnosis.

RESULTS

There were significant differences between the 2 groups in T1_5min, T1_60min, and T1_differ values (P = .012, P = .004, and P < .001, respectively). Relative to T1_5min and T1_60min, T1_differ exhibited greater sensitivity and specificity (P < .001, respectively) in identifying radionecrosis. The optimum T1_differ value for differential diagnosis was 71.1 ms (area under the curve = 0.97; 95% CI, 0.93-1.00), with sensitivity and specificity of 81.5% and 96.5%, respectively.

CONCLUSIONS

Postcontrast T1 mapping is optimal for the differential diagnosis of radionecrosis and tumor recurrence. Among T1 parameters, T1_differ is the most powerful parameter for differential diagnosis. Advantages in terms of quantitative analysis and high resolution portend the wide use of postcontrast T1 mapping in the future.

Selective growth of two-dimensional phosphorene on catalyst surface

Although the study of black phosphorene (BP) and its isomers has attracted enormous attention, the method of synthesizing high-quality samples in a large area is still pending. Here we explore the potential of using the chemical vapor deposition method to synthesize large-area two-dimensional (2D) phosphorene films on metal surfaces. Our ab initio calculations show that BP can be synthesized by using tin (Sn) as a catalyst, while one of its isomers, blue phosphorene (BLP), is very possible to be synthesized by using most other metals, such as Ag and Au. Besides, our study also suggests that the large binding energy between the 2D phosphorene and the active metal substrate may prohibit the exfoliation of the 2D phosphorene for real applications and, therefore, tin, silver and gold are predicted to be the most suitable catalysts for the synthesis of BP and BLP.

Measurement of the spin temperature of optically cooled nuclei and GaAs hyperfine constants in GaAs/AlGaAs quantum dots

Deep cooling of electron and nuclear spins is equivalent to achieving polarization degrees close to 100% and is a key requirement in solid-state quantum information technologies. While polarization of individual nuclear spins in diamond and SiC (ref. ) reaches 99% and beyond, it has been limited to 50-65% for the nuclei in quantum dots. Theoretical models have attributed this limit to formation of coherent 'dark' nuclear spin states but experimental verification is lacking, especially due to the poor accuracy of polarization degree measurements. Here we measure the nuclear polarization in GaAs/AlGaAs quantum dots with high accuracy using a new approach enabled by manipulation of the nuclear spin states with radiofrequency pulses. Polarizations up to 80% are observed-the highest reported so far for optical cooling in quantum dots. This value is still not limited by nuclear coherence effects. Instead we find that optically cooled nuclei are well described within a classical spin temperature framework. Our findings unlock a route for further progress towards quantum dot electron spin qubits where deep cooling of the mesoscopic nuclear spin ensemble is used to achieve long qubit coherence. Moreover, GaAs hyperfine material constants are measured here experimentally for the first time.