The loss of dissolved organic matter from biological soil crust at various successional stages under rainfall of different intensities: Insights into the changes of molecular components at different rainfall stages.

Biological soil crusts (BSCs) are typical covers in arid and semiarid regions. The dissolved organic matter (DOM) of BSCs can be transported to various aquatic ecosystems by rainfall-runoff processes. However, the spatiotemporal variation in quality and quantity of DOM in runoff remains unclear. Herein, four kinds of runoff plots covered by four successional stages of BSCs were set up on slopes, including bare runoff plot (BR), cyanobacteria crust covered runoff plot (CR), mixed crust covered runoff plot (MIR), and moss crust covered runoff plot (MOR). The quantity and quality of DOM in runoff during rainfall was investigated based on the stimulated rainfall experiments combined with optical spectroscopy and ultra-high resolution mass spectrometry analyses. The results showed that the DOM concentrations (i.e., 0.30 to 45.25 mg L-1) in runoff followed the pattern of MOR>MIR>CR>BR, and they were exponentially decreased with rainfall duration. The DOM loss rate of BR (8.26 to 11.64 %) was significantly greater than those of CR, MIR, and MOR (0.84 to 3.22 %). Highly unsaturated compounds (HUCs), unsaturated aliphatic compounds (UACs), saturated compounds (SCs), and peptide-like compounds (PLCs) were the dominated compounds of the water extractable DOM from the original soils. Thereinto, PLCs and UACs were more easily leached into runoff during rainfall. The relatively intensity of HUCs in runoff generally decreased with rainfall duration, while the relatively intensities of UACs, PLCs, and SCs slightly increased with rainfall duration. These findings suggested that the DOM loss rate was effectively decreased with the successional of BSCs during rainfall; meanwhile, some labile compounds (e.g., PLCs and UACs) were transported into various aquatic ecosystems by rainfall-runoff processes.

Hematoporphyrin derivative-mediated photodynamic techniques for the diagnosis and treatment of chordoma.

BACKGROUND: Chordoma is a rare congenital low-grade malignant tumor characterized by infiltrative growth. It often tends to compress important intracranial nerves and blood vessels, making its surgical treatment extremely difficult. Besides, the efficacy of radiotherapy and chemotherapy is limited. The photosensitizer hematoporphyrin derivative (HPD) can emit red fluorescence under 405 nm excitation and produce reactive oxygen species for tumor therapy under 630 nm excitation. Herein, we investigated the effects of the photosensitizer hematoporphyrin derivative (HPD) on different cell lines of chordoma and xenograft tumors under 405 nm and 630 nm excitation. METHODS: The photosensitizer hematoporphyrin derivative (HPD) and Two different chordoma cell lines (U-CH1, JHC7) were used for the test. The in vitro experiments were as follows: (1) the fluorescence intensity emitted by chordoma cells excited by different 405 nm light intensities was observed under a confocal microscope; (2) the Cell Counting Kit-8 (CCK-8) assay was performed to detect the effects of different photosensitizer concentrations and 630 nm light energy densities on the activity of chordoma cells. In the in vivo experiments, (3) Fluorescence visualization of chordoma xenograft tumors injected with photosensitizer via tail vein under 405 nm excitation; (4) Impact of 630 nm excitation of photosensitizer on the growth of chordoma xenograft tumors. RESULTS: (1) The photosensitizers in chordoma cells and chordoma xenografts of nude mice were excited by 405nm to emit red fluorescence; (2) 630 nm excitation photosensitizer reduces chordoma cell activity and inhibits chordoma xenograft tumor growth in chordoma nude mice. CONCLUSION: Photodynamic techniques mediated by the photosensitizer hematoporphyrin derivatives can be used for the diagnosis and treatment of chordoma.

Structurally diverse cucurbitane-type triterpenoids from the tubers of Hemsleya chinensis with cytotoxic activity.

Ten previously undescribed cucurbitane-type triterpenoids, namely hemslyencins A-F (1-6) and hemslyencosides A-D (7-10), together with twenty previously reported compounds (11-30), were isolated from the tubers of Hemsleya chinensis. Their structures were elucidated by unambiguous spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR data). Hemslyencins A and B (1 and 2) possessing unique 9, 11-seco-ring system with a six-membered lactone moiety, were the first examples among of the cucurbitane-type triterpenoids, and hemslyencins C and D (3 and 4) and hemslyencoside D (10) are the infrequent pentacyclic cucurbitane triterpenes featuring a 6/6/6/5/6 fused system. The cytotoxic activities of all isolated compounds were evaluated against MCF-7, HCT-116, HeLa, and HepG2 cancer cells, and their structure-activity relationships (SARs) was discussed as well. Compounds 17, 25, and 26 showed significant cytotoxic effects with IC50 values ranging from 1.31 to 9.89 µM, among which compound 25 induced both apoptosis and cell cycle arrest at G2/M phase in a dose dependent manner against MCF-7 cells.

Genetic testing of sperm donors in China: a survey of current practices.

Background: The National Health and Family Planning Commission of China (NHFPCC) issued the "Measures for the Management of Human Sperm Banks," which was revised in 2003 and is still in effect today. One of the standard guidelines is that potential donors undergo laboratory testing to exclude infectious and genetic diseases and karyotype analysis. However, patient demands for donor genetic testing have also increased, and only karyotype analysis to exclude genetic diseases is not sufficient to meet these demands. Objective: To examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks. Materials and methods: An electronic survey was distributed to twenty-seven sperm banks to examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks. Twenty-six human sperm banks responded to a 32-question survey about their current practices related to genetic testing of sperm donors. Results: The 26 sperm banks reported that all qualified sperm donors undergo karyotype analysis; 22 banks (84.6%) collected three generations of family history from each qualified sperm donor; 10 (38.5%) reported that they attempted to accommodate special requests from donor semen recipients for particular genetic tests. Only 2 of the 26 (7.7%) sperm banks reported that they performed whole-exome sequencing. At all the sperm banks, consent for genetic testing was obtained as part of the overall contract for sperm donors. Nineteen (73.1%) sperm banks had genetic counselors on their staff, while six (23.1%) had no genetic counselors on their staff but had access to genetic counselors at the hospital. Only one (3.8%) sperm bank had no genetic counselors on their staff or at the hospital. Conclusions: The need for larger scale genetic testing of donors and recipients and an extensive panel of genetic tests specific to the Chinese population. Additionally, professionally trained geneticists must be employed as genetic counsellors so that the results of genetic tests and their implications can be explained to donors.

Specific changes and clinical significance of plasma D-dimer during pregnancy and puerperium: a prospective study.

BACKGROUND: Pregnant and puerperal women are high-risk populations for developing venous thromboembolism (VTE). Plasma D-dimer (D-D) is of good value in the diagnosis of exclusion of VTE in the nonpregnant population. Since there is no consensus reference range of plasma D-D applicable to pregnant and puerperal women, the application of plasma D-D is limited. To investigate the change characteristics and the reference range of plasma D-D levels during pregnancy and puerperium and to explore the pregnancy- and childbirth-related factors affecting plasma D-D levels and the diagnostic efficacy of plasma D-D for excluding VTE during early puerperium after caesarean section. METHODS: A prospective cohort study was conducted with 514 pregnant and puerperal women (cohort 1), and 29 puerperal women developed VTE 24-48 h after caesarean section (cohort 2). In cohort 1, the effects of the pregnancy- and childbirth-related factors on the plasma D-D levels were analyzed by comparing the differences in plasma D-D levels between different groups and between different subgroups. The 95th percentiles were calculated to establish the unilateral upper limits of the plasma D-D levels. The plasma D-D levels at 24-48 h postpartum were compared between normal singleton pregnant and puerperal women in cohort 2 and women from the cesarean section subgroup in cohort 1, binary logistic analysis was used to analyze the relevance between plasma D-D level and the risk of VTE developing 24-48 h after caesarean section, and a receiver operating characteristic (ROC) curve was used to assess the diagnostic efficacy of plasma D-D for excluding VTE during early puerperium after caesarean section. RESULTS: The 95% reference ranges of plasma D-D levels in the normal singleton pregnancy group were ≤ 1.01 mg/L in the first trimester, ≤ 3.17 mg/L in the second trimester, ≤ 5.35 mg/L in the third trimester, ≤ 5.47 mg/L at 24-48 h postpartum, and ≤ 0.66 mg/L at 42 days postpartum. The plasma D-D levels of the normal twin pregnancy group were significantly higher than those of the normal singleton pregnancy group during pregnancy (P < 0.05), the plasma D-D levels of the GDM group in the third trimester were significantly higher than those of the normal singleton pregnancy group (P < 0.05). The plasma D-D levels of the advanced age subgroup at 24-48 h postpartum were significantly higher than those of the nonadvanced age subgroup (P < 0.05), and the plasma D-D levels of the caesarean section subgroup at 24-48 h postpartum were significantly higher than those of the vaginal delivery subgroup (P < 0.05). The plasma D-D level was significantly correlated with the risk of VTE developing at 24-48 h after caesarean section (OR = 2.252, 95% CI: 1.611-3.149). The optimal cut-off value of plasma D-D for the diagnosis of exclusion of VTE during early puerperium after caesarean section was 3.24 mg/L. The negative predictive value for the diagnosis of exclusion of VTE was 96.1%, and the area under the curve (AUC) was 0.816, P < 0.001. CONCLUSIONS: The thresholds of plasma D-D levels in normal singleton pregnancy and parturient women were higher than those of nonpregnant women. Plasma D-D had good value in the diagnosis of exclusion of VTE occurring during early puerperium after caesarean section. Further studies are needed to validate these reference ranges and assess the effects of pregnancy- and childbirth-related factors on plasma D-D levels and the diagnostic efficacy of plasma D-D for excluding VTE during pregnancy and puerperium.

Five New C21 -Steroidal Sapogenins from the Acid Hydrolysate of Cynanchum otophyllum Roots.

Five new C21 -steroidal sapogenins (1-5) named cynotogenins J-N, were isolated from the acid hydrolysate of Cynanchum otophyllum roots. Their structures were established by extensive spectroscopic analysis (UV, IR, HR-ESI-MS, and NMR). Most notably, compounds 1-3 harboring a rare 5ß,6ß-epoxy group in the C21 -steroidal skeleton of Cynanchum plants. All compounds were evaluated for their cytotoxicities against multiple cancer cell lines, in which compounds 5 showed weak cytotoxicity against HepG2 cancer cells with IC50 values of 44.90 µM.

Organophosphine as an Alkyl Transfer Shuttle for the Direct ß-Alkylation of Chalcones Using Alkyl Halides.

We report an efficient alkyl transfer strategy for the direct ß-alkylation of chalcones using commercially available alkyl bromides as alkyl reagents. In this transformation, the ortho-phosphanyl substituent in the chalcones is crucial for controlling their reactivity and selectivity. It also serves as a reliable alkyl transfer shuttle to transform electrophilic alkyl bromides into nucleophilic alkyl species in the form of quaternary phosphonium salts and transfer the alkyl group effectively to the ß-position of the chalcones. This alkyl transfer strategy can be further extended to the alkenylation of ortho-phosphanyl benzaldehydes to assemble functionalized polyenes.

Three new cardenolides from the fruits of Cascabela thevetia (L.) Lippold and their cytotoxic activities.

Phytochemical investigations on the fruits of Cascabela thevetia (L.) Lippold led to obtain three new cardenolides (1-3) and five known analogues (4-7). Their structures were elucidated by means of UV, IR, HR-ESI-MS, 1D and 2D NMR spectroscopic data analysis. Compounds 1 and 2 represent the first examples of naturally occurring cardenolides with 19-nor-5(10)-ene group and α-l-3-demethyl-thevetose, respectively. Compound 3 is a rare C-nor-D-homocardenolide in nature. All isolated cardenolides (1-7) were evaluated for their cytotoxic activities against four human cancer cell lines (MCF-7, HCT-116, HeLa and HepG2), and the results indicated the compounds with sugar units (1, 2, 4, and 5) exhibited stronger cytotoxic activities with IC50 values ranging between 0.022 and 0.308 µM.

The regulatory mechanisms by enhancers during cancer initiation and progression.

Enhancer is a DNA sequence, and mainly acts in cis to regulate gene transcription. Due to the uncertainty in both location and distance between enhancers and their target genes, it is more complex and difficult to study the underlying regulatory mechanism of enhancers. Accumulating evidences indicate that enhancers are closely associated with the occurrence and development of diseases, such as cancer. Therefore, the studies of enhancers in cancer will be helpful to deeply unravel cancer pathogenesis and to promote the development of antitumor drugs. The related research is with great social significance and economic value. Currently, the identification of enhancers is insufficient. The regulatory mechanisms by enhancers during the initiation and progression of cancer and other diseases have not been fully delineated. In this review, we provide an overview of enhancers, super enhancers and their properties, followed by a description of enhancer prediction and identification at the genome-wide level. Finally, we summarize the regulatory roles of enhancers during diseases such as cancer in recent years, thereby providing a reference for the future exploration on enhancer regulatory mechanisms as well as cancer diagnosis and treatment.

Dearomative Periphery Modification of Quinolinium Salts to Assemble Ring-Encumbered Pyrrolidine-Tetrahydroquinoline Polycycles.

We report an unexpected dearomative periphery modification strategy for transforming quinolinium salts into structurally crowded pyrrolidine-tetrahydroquinoline polycyclic systems with complete regio- and diastereoselectivity. Importantly, the reaction pathway was regulated by simply tuning the substituents, achieving substituent-directed divergent synthesis. The notable features of this transformation include readily available starting materials, green conditions, a simple workup procedure, high bond- and ring-forming efficiency, and substituent-directed diverse synthesis.

Synthesis and biological evaluation of 3ß-O-neoglycosides of caudatin and its analogues as potential anticancer agents.

In order to study the structure-activity relationship (SAR) of C21-steroidal glycosides toward human cancer cell lines and explore more potential anticancer agents, a series of 3ß-O-neoglycosides of caudatin and its analogues were synthesized. The results revealed that most of peracetylated 3ß-O-monoglycosides demonstrated moderate to significant antiproliferative activities against four human cancer cell lines (MCF-7, HCT-116, HeLa, and HepG2). Among them, 3ß-O-(2,3,4-tri-O-acetyl-ß-L-glucopyranosyl)-caudatin (2k) exhibited the highest antiproliferative activity aganist HepG2 cells with an IC50 value of 3.11 µM. Mechanical studies showed that compound 2k induced both apoptosis and cell cycle arrest at S phase in a dose dependent manner. Overall, these present findings suggested that glycosylation is a promising scaffold to improve anticancer activity for naturally occurring C21-steroidal aglycones, and compound 2k represents a potential anticancer agent deserved further investigation.

3D Digital Evaluation for Direct Composite Restoration Using the Modified Stamp Technique.

OBJECTIVE: To evaluate the clinical performance of direct composite restorations using the modified stamp technique (MST) in vivo. METHODS: A total of 30 posterior teeth with undermining caries were randomly divided into two groups and then restored using the MST and conventional technique (CT), respectively. 3D images of the occlusal surface were obtained using an intraoral scanner (CEREC Omnicam, Dentsply Sirona, Charlotte, NC, USA) before and after treatment and the differences between these two 3D images were analysed with reverse engineering software. Statistical analysis was performed using a one-way analysis of variance (ANOVA) combined with a least significant difference (LSD) post hoc test using SPSS 20.0 software (IBM, Armonk, NY, USA). RESULTS: The statistical analysis revealed that the average root mean square (RMS) values of best fit alignment errors were significantly different between groups (P < 0.01). The average RMS values in the MST and CT groups were 0.0738 ± 0.0279 and 0.1638 ± 0.0682, respectively. The LSD post hoc test revealed that the value was significant smaller in the MST group than in the CT group. CONCLUSION: The MST was effective in direct composite restoration. The morphological consistency of the occlusal surface using the MST was better than with the CT.

Regioselective and Diastereoselective Dearomative Multifunctionalization of In-Situ-Activated Azaarenes: An Access to Bridged Azaheterocycles.

Reported herein is an unprecedented multicomponent one-pot dearomative multifunctionalization of commercially available azaarenes through an in situ activation strategy, which not only achieved the first full exploitation of the reactive sites of the azaarenes, but also accomplished the efficient synthesis of bridged hydrogenated pyridines and (iso)quinolines in a highly regioselective and diastereoselective manner. In addition, we could successfully realize the step-controlled dearomative trifunctionalization and bifunctionalization of quinolines.

Chalcone-Based Pyridinium Salts and Their Diastereoselective Dearomatization To Access Bibridged Benzoazepines.

New chalcone-based pyridinium salts have been successfully exploited, which could smoothly participate in the highly diastereoselective dearomatization with binucleophilic enaminones by taking advantage of their multiple reactive sites to construct bibridged benzoazepines in up to 89% yields. The key to the success was the skillful and unprecedented C-3 functionalization of the new pyridinium salts. This work not only provides a kind of novel pyridinium salt synthon but also achieves the first C-3 functionalization of pyridinium salts to construct complex and challenging bibridged benzoazepines with high synthetic efficiency.

Protective effects of 3ß-angeloyloxy-8ß, 10ß-dihydroxyeremophila-7(11)-en-12, 8α-lactone on paraquat-induced oxidative injury in SH-SY5Y cells.

3ß-Angeloyloxy-8ß,10ß-dihydroxyeremophila-7(11)-en-12,8α-lactone (FJ1) inhibited effectively paraquat (PQ)-induced injury in SH-SY5Y cells. In this way, FJ1 was shown to reverse the PQ-induced activation of caspase-9 and caspase-3, the increase in Bax/Bcl-2 ratio, and the release of cytochrome c. The mechanism was associated with a reduction of oxidative stress, including the decrease in the levels of ROS and MDA and maintaining the activity of SOD and GSH. Taken together, findings revealed that FJ1 had protective effects against PQ-induced injury via attenuating the oxidative stress in SH-SY5Y cells, which suggested that FJ1 might be a candidate for further evaluation against neurodegeneration in Parkinson's disease.

Regio- and diastereoselective dearomatizations of N-alkyl activated azaarenes: the maximization of the reactive sites.

An unprecedented base-promoted multi-component one-pot dearomatization of N-alkyl activated azaarenes was developed, which enabled the synthesis of complex and diverse bridged cyclic polycycles with multiple stereocenters in a highly regio- and diastereoselective manner. Besides, we realized the step-controlled dearomative bi- and trifunctionalization of quinolinium salts. These transformations not only achieved the maximization of the reaction sites of pyridinium, quinolinium and isoquinolinium salts to enhance structural complexity and diversity, but also opened up a new reaction mode of these N-activated azaarenes. A unique feature of this strategy is the use of easily accessible and bench-stable N-alkyl activated azaarenes to provide maximum reactive sites for dearomative cascade cyclizations. In addition, the salient characteristics including high synthetic efficiency, short reaction time, mild conditions and simple operation made this strategy particularly attractive.

A modified clinicopathological tumor staging system for survival prediction of patients with penile cancer.

BACKGROUND: The 8th American Joint Committee on Cancer tumor-node-metastasis (AJCC-TNM) staging system is based on a few retrospective single-center studies. We aimed to test the prognostic validity of the staging system and to determine whether a modified clinicopathological tumor staging system that includes lymphovascular embolization could increase the accuracy of prognostic prediction for patients with stage T2-3 penile cancer. METHODS: A training cohort of 411 patients who were treated at 2 centers in China and Brazil between 2000 and 2015 were staged according to the 8th AJCC-TNM staging system. The internal validation was analyzed by bootstrap-corrected C-indexes (resampled 1000 times). Data from 436 patients who were treated at 15 centers over four continents were used for external validation. RESULTS: A survivorship overlap was observed between T2 and T3 patients (P = 0.587) classified according to the 8th AJCC-TNM staging system. Lymphovascular embolization was a significant prognostic factor for metastasis and survival (all P < 0.001). Based on the multivariate analysis, only lymphovascular embolization showed a significant influence on cancer-specific survival (CSS) (hazard ratio = 1.587, 95% confidence interval = 1.253-2.011; P = 0.001). T2 and T3 patients with lymphovascular embolization showed significantly shorter CSS than did those without lymphovascular embolization (P < 0.001). Therefore, a modified clinicopathological staging system was proposed, with the T2 and T3 categories of the 8th AJCC-TNM staging system being subdivided into two new categories as follows: t2 tumors invade the corpus spongiosum and/or corpora cavernosa and/or urethra without lymphovascular invasion, and t3 tumors invade the corpus spongiosum and/or corpora cavernosa and/or urethra with lymphovascular invasion. The modified staging system involving lymphovascular embolization showed improved prognostic stratification with significant differences in CSS among all categories (all P < 0.005) and exhibited higher accuracy in predicting patient prognoses than did the 8th AJCC-TNM staging system (C-index, 0.739 vs. 0.696). These results were confirmed in the external validation cohort. CONCLUSIONS: T2-3 penile cancers are heterogeneous, and a modified clinicopathological staging system that incorporates lymphovascular embolization may better predict the prognosis of patients with penile cancer than does the 8th AJCC-TNM staging system. Trial registration This study was retrospectively registered on Chinese Clinical Trail Registry: ChiCTR16008041 (2016-03-02). http://www.chictr.org.cn.

QTL Mapping and Validation of Adult Plant Resistance to Stripe Rust in Chinese Wheat Landrace Humai 15.

Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a devastating foliar disease that affects common wheat and barley throughout the world. The reasonable deployment of adult plant resistance (APR) wheat varieties is one of the best methods for controlling this disease. Wheat landraces are valuable resources for identifying the genes/QTLs responsible for disease resistance. Humai 15 is a Chinese spring wheat landrace and it has exhibited adequate levels of APR to the prevalent Pst races in field environments for many years. In this study, a population of 177 recombinant inbred lines (RILs) was derived from Humai 15 × Mingxian 169. After screening based on a 90K chip array using 45 RILs and Kompetitive Allelic Specific PCR marker genotyping for the population of RILs, a major effect QTL in Humai 15 was located on the centromere of chromosome 2B, where it accounted for up to 47.2% of the phenotypic variation. Two other minor QTL genes from Humai 15 were located on chromosome arms 3BS and 4BL. The Yr18 gene was identified on chromosome arm 7DS in Mingxian 169.

Diastereoselective construction of 4-indole substituted chromans bearing a ketal motif through a three-component Friedel-Crafts alkylation/ketalization sequence.

The first TfOH-catalyzed three-component Friedel-Crafts alkylation/ketalization sequence of indoles, alcohols and ortho-hydroxychalcones was developed to afford a wide range of 4-indole substituted chromans bearing a ketal motif in 77-99% yields. Notably, only a simple filtration was needed to purify them. By altering methanol to CHCl3, 2,4-bisindole substituted chroman with the same indole substituent at the C2 and C4 positions was afforded. Moreover, 2,4-bisindole substituted chromans with different indole substituents could be obtained by treatment of 4-indole monosubstituted chromans with another indole molecule.

Overexpression of lncRNA ANRIL promoted the proliferation and migration of prostate cancer cells via regulating let-7a/TGF-ß1/ Smad signaling pathway.

Long non-coding RNAs (lncRNAs) were playing critical roles in tumorigenesis. However, in prostate cancer, the roles and mechanisms of lncRNAs especially ANRIL were largely unknown. We investigated the effects of ANRIL on the proliferation and migration of prostate cancer cells using CCK-8 assay and Transwell migration assay. Real-time PCR and western blotting assays were used to analyze the levels of ANRIL, let-7a, TGF-ß1, p-Smad2 and p-Smad7. Our results showed that ANRIL was significantly overexpressed in prostate cancer tissues compared with corresponding normal tissues. Knockdown of ANRIL significantly inhibited the proliferation and migration of prostate cancer LNCap, PC3 and DU145 cells. Knockdown of ANRIL significantly decreased the levels of TGF-ß1 and p-Smad2, and increased the level of p-Smad7 in prostate cancer LNCap cells. We further found that knockdown of ANRIL significantly enhanced the expression of let-7a, and rescue experiment found that let-7a inhibitor recovered the suppressive effects of ANRIL silencing on the proliferation and migration of prostate cancer LNCap, PC3 and DU145 cells. And let-7a inhibitor recovered the suppressive effects of ANRIL silencing on the activity of TGF-ß1/Smad signaling pathway in prostate cancer LNCap cells. Taken together, our findings indicated that overexpression of lncRNA ANRIL promoted the proliferation and migration of prostate cancer cells via regulating let-7a/TGF-ß1/Smad signaling pathway.