Uncommon Epoxyquinols Pyrrolocytosporin A and cytosporin E2from the Fungus Eutypella sp. D-1

Two uncommon epoxyquinols, pyrrolocytosporin A (1) and cytosporin E2 (2), along with the known cytosporin Y1 (3), were isolated from the solid defined medium of the Arctic-derived fungus Eutypella sp. D-1. Their structures were established through comprehensive analyses of spectroscopic and electronic circular dichroism data. Structurally, compound 1 represented the first nitrogen-containing epoxyquinol characterized by a pyrrole fused cytosporin framework, while compound 2 contained an uncommon cyclic carbonate functionality. The antibacterial, immunosuppressive, anti-inflammatory, and cytotoxic activities of all compounds were evaluated. Among the three metabolites, only compound 1 exhibited inhibitory effects on nitric oxide production induced by lipopolysaccharide with an IC50 value of 6.55 μM. Additionally, only compound 2 displayed inhibitory activity against ConA-induced T-cell proliferation with an IC50 value of 9.85 μM.

Eutypellaolides A-J, Sesquiterpene diversity expansion of the polar fungus Eutypella sp. D-1

Eight new 12,8-eudesmanolide sesquiterpenes, eutypellaolides A-H (1-8), and two new eudesmane-type sesquiterpenes, eutypellaolides I-J (9-10), along with four known 12,8-eudesmanolide compounds 11-14, were isolated from the culture extract of the polar fungus Eutypella sp. D-1 by one strain many compounds (OSMAC) approach. The structures of these compounds were determined through comprehensive spectroscopic data and experimental and calculated ECD analysis. Antibacterial, immunosuppressive, and PTP1B inhibition activities of these compounds were evaluated. Compounds 1 and 11 exhibited strong inhibitory activities against Bacillus subtilis and Staphylococcus aureus, with each showing an MIC value of 2 μg/mL. Compound 9 displayed weak immunosuppressive activity against ConA-induced T-cell proliferation with an inhibitory rate of 61.7% at a concentration of 19.8 μM. Compounds 5, 11, and 14 exhibited weak PTP1B inhibition activities with IC50 values of 44.8, 43.2, and 49.5 μM, respectively.

Phyllofenones F-M, Scalarane Sesterterpenes from the Marine Sponge Phyllospongia foliascens

Eight new scalarane sesterterpenes, phyllofenones F-M (1-8), together with two known analogues, carteriofenones B and A (9-10), were isolated from the marine sponge Phyllospongia foliascens collected from the South China Sea. The structures of these compounds were determined based on extensive spectroscopic and quantum chemical calculation analysis. The antibacterial and cytotoxic activity of these compounds was evaluated. Among them, only compounds 4 and 6 displayed weak inhibitory activity against Staphylococcus aureus and Escherichia coli, with MIC values of 16 μg/mL and 8 μg/mL, respectively. Compounds 1-10 exhibited cytotoxic activity against the HeLa, HCT-116, H460, and SW1990 cancer cell lines, with IC50 values ranging from 3.4 to 19.8 μM.

Cytosporin Derivatives from Arctic-Derived Fungus Eutypella sp. D-1 via the OSMAC Approach

A chemical investigation of the Arctic-derived fungus Eutypella sp. D-1 based on the OSMAC (one strain many compounds) approach resulted in the isolation of five cytosporin polyketides (compounds 1-3 and 11-12) from rice medium and eight cytosporins (compounds 2 and 4-11) from solid defined medium. The structures of the seven new compounds, eutypelleudesmane A (1), cytosporin Y (2), cytosporin Z (3), cytosporin Y₁ (4), cytosporin Y₂ (5), cytosporin Y₃ (6), and cytosporin E₁ (7), were elucidated by analyzing their detailed spectroscopic data. Structurally, cytosporin Y₁ (4) may be a key intermediate in the biosynthesis of the isolated cytosporins, rather than an end product. Compound 1 contained a unique skeleton formed by the ester linkage of two moieties, cytosporin F (12) and the eudesmane-type sesquiterpene dihydroalanto glycol. Additionally, the occurrence of cyclic carbonate moieties in compounds 6 and 7 was found to be rare in nature. The antibacterial, immunosuppressive, and cytotoxic activities of all compounds derived from Eutypella sp. D-1 were evaluated. Unfortunately, only compounds 3, 6, 8, and 10-11 displayed immunosuppressive activity, with inhibitory rates of 62.9%, 59.5%, 67.8%, 55.8%, and 68.7%, respectively, at a concentration of 5 μg/mL.

Phyllospongianes A-E, Dinorscalarane Sesterterpenes from the Marine Sponge Phyllospongia foliascens

Phyllospongianes A-E (1-5), five new scalarane derivatives featuring an unprecedented 6/6/6/5 tetracyclic dinorscalarane scaffold, along with the known probable biogenetic precursor, 12-deacetylscalaradial (6), were isolated from the marine sponge Phyllospongia foliascens. The structures of the isolated compounds were determined by analysis of spectroscopic data and electronic circular dichroism experiments. Compounds 1-5 are the first 6/6/6/5 tetracyclic scalarane derivatives to be reported within the scalarane family. Compounds 1, 2, and 4 exhibited antibacterial activity against Vibrio vulnificus, Vibrio parahemolyticus, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and Pseudomonas aeruginosa with MIC values ranging from 1 to 8 μg/mL. Furthermore, compound 3 exhibited significant cytotoxic activity on MDA-MB-231, HepG2, C4-2-ENZ, MCF-7, H460, and HT-29 cancer cell lines with IC₅₀ values in the range between 0.7 and 13.2 μM.

[The success rate of His-Purkinje system pacing in patients with various sites of atrioventricular block]

Objective: To evaluate the success rate of His-Purkinje system pacing (HPSP) in patients with various sites of atrioventricular block (AVB) and provide clinical evidence for the selection of HPSP in patients with AVB. Methods: This is a retrospective case analysis. 637 patients with AVB who underwent permanent cardiac pacemaker implantation and requiring high proportion of ventricular pacing from March 2016 to September 2021 in the Department of Cardiology, General Hospital of Northern Theater Command were enrolled. The site of AVB was determined by electrophysiological examination. His bundle pacing (HBP) was performed in the first 130 patients (20.4%) who were classified as the HBP group and HPSP included HBP and/or left bundle branch pacing (LBBP) was performed in later 507 patients (79.6%) and these patients were classified as the HPSP group. The basic clinical information such as age and sex of the two groups was compared, and the success rates of HBP or HPSP in patients with different sites of AVB and QRS intervals were analyzed. Results: The age of HBP group was (66.4±15.9) years with 75 males (57.7%). The age of HPSP group was (66.8±13.6) years with 288 (56.8%) males. Among 637 patients, 63.0% (401/637) had atrioventricular node block; 22.9% (146/637) had intra-His block; 14.1% (90/637) had distal or inferior His bundle block. Totally, the success rate of HPSP was higher than that of HBP [93.9% (476/507) vs. 86.9% (113/130), P<0.05]. In each group of patients with various AVB sites, the success rate of HPSP was higher than that of HBP respectively and both success rates of HBP and HPSP showed a declining trend with the distant AVB site. The success rate of HBP in patients with atrioventricular node block and intra-His block was higher than that in patients with distal or inferior His bundle block [95.2% (79/83) vs. 47.1% (8/17), P<0.001; 86.7% (26/30) vs. 47.1% (8/17), P=0.010]. The success rate of HPSP was higher than that of HBP in patients with distal or inferior His bundle block [87.7% (64/73) vs 47.1% (8/17), P=0.001]. In patients with QRS<120 ms, 94.9% (520/548) of AVB sites were in atrioventricular node or intra-His, and HBP had a similar high success rate with HPSP [95.6% (109/114) vs. 96.3% (418/434), P=0.943] in these patients. In patients with QRS ≥ 120 ms, 69.7% (62/89) of AVB sites were at distal or inferior His bundle, and the success rate of HBP was only 25.0% (4/16), while the success rate of HPSP was as high as 79.5% (58/73), P<0.001. Conclusions: In patients with QRS<120 ms and atrioventricular node block or intra-His block, success rates of HBP and HPSP are similarly high and HBP might be considered as the first choice. In patients with QRS ≥ 120 ms and AVB site at distal or inferior His bundle, the success rate of HPSP is higher than that of HBP, suggesting LBBP should be considered as the first-line treatment option.

Bioactive Scalarane-Type Sesterterpenoids from Marine Sources

Scalarane-type sesterterpenoids have received considerable attention in the scientific literature due to their diverse carbon skeletons and various biological activities and pharmacological properties. Among all these derivatives are commonly isolated from marine sponges and are occasionally derived from shell-less mollusks, such as nudibranchs. This review comprehensively discusses the marine-derived natural sources that give rise to these scalarane-type sesterterpenoids, providing the names, their chemical structures, biological properties, with emphasis on anticancer activity and literature references related to these metabolites. A critical summary of the 221 compounds generated from January 2010 up to December 2021 for their potential as anticancer agents is presented.

[Identification of rare variants in exons of NLRC4 gene in patients with type 1 diabetes and their impact on gene function]

Objective: To identify rare variants in exon and exon-intron boundary of containing NLR family CARD domain protein 4 (NLRC4) in type 1 diabetes (T1DM) patients, and to explore their effects on gene function. Methods: A total of 508 T1DM patients and 527 healthy controls in the Department of Metabolic Endocrinology, Second Xiangya Hospital of Central South University from August 2017 to September 2020 were selected. The case group included 264 males and 244 females, and the age [M (Q₁, Q₃)] was [27 (11, 43)] years. The control group included 290 males and 237 females, and their age［M（Q₁，Q₃）］was [47 (36, 60)] years old. Identification of rare variants in exons of NLRC4 gene in T1DM patients and healthy controls was performed and verified by next-generation sequencing and sanger sequencing. The NLRC4 gene wild-type and mutant plasmids were constructed and transfected into 293T cells. Western blot (WB) was used to detect the expression of NLRC4 protein and cleavage products of pro-cysteinyl aspartate specific proteinase(procaspase-1). Cycloheximide (CHX) was added to 293T cells transfected with wild-type or mutant NLRC4 plasmid to detect the degradation of NLRC4 protein. The localization of NLRC4 protein was detected by immunofluorescence, and the concentration of IL-1β in the cell supernatant was detected by enzyme-linked immunosorbent assay (ELISA). Results: The sequencing results showed that 4 patients and 2 healthy controls had a heterozygous variant c.208C>T in exon 3 of the NLRC4 gene. Two patient had a heterozygous variant c.1564T>C in exon 4, and 1 patients had c.1219G>C in exon 4. These three variants might be pathogenic variants in T1DM. In 293T cells transfected with NLRC4 wild-type and c.208C>T、c.1564T>Cc.1219G>C mutant plasmids, the expression level, degradation rate, localization of NLRC4 protein and the content of cleavage products of procaspase-1 did not change significantly. However, the concentration of IL-1β secreted by 293T cells transfected with c.1219G>C and c.208C>T plasmid [M(Q₁, Q₃)] was 15.25 (12.98, 17.52) and 15.44 (13.81, 17.07) ng/L, respectively, which was lower than 18.70 (16.59, 20.81) ng/L of 293T cells transfected wild-type plasmid (P=0.020, 0.010). Conclusions: NLRC4 gene rare variants c.208C>T, c.1564T>C and c.1219G>C may not change the protein expression, degradation and localization, but c.208C>T and c.1219G>C may inhibit the secretion of IL-1β. This result suggests that NLRC4 rare variants may have an impact on gene function.

[A real-world study of the efficacy and safety of sofosbuvir and velpatasvir in the treatment of HCV-infected patients in a county in northern China]

Objective: To evaluate the real-world efficacy and safety of sofosbuvir and velpatasvir (SOF/VEL) tablets in the treatment of Chinese patients with chronic HCV infection. Methods: An open-label, single-center, prospective clinical study was conducted in a county in northern China. A total of 299 cases were enrolled. Of these, 161 cases with chronic hepatitis C and 73 cases with compensated cirrhosis received SOF/VEL for 12 weeks. 65 cases with decompensated cirrhosis received SOF/VEL combined with ribavirin for 12 weeks (22 cases) or SOF/VEL for 24 weeks (43 cases). Virological indicators, liver and renal function indexes, and liver stiffness measurement were detected at baseline, the fourth week of treatment, the end of treatment, and the 12-weeks of follow-up. Adverse reactions and laboratory abnormalities were observed during the course of treatment . The primary endpoint was undetectable rate of HCV RNA (SVR12) at 12 weeks of follow-up with the use of modified intention-to-treat (mITT) approach. Measurement data between two groups were compared using t-test. One Way ANOVA was used for comparison between multiple groups. Enumeration data were analyzed by chi-square test or Fisher's exact test. Results: 291 cases had completed treatment. HCV RNA was undetectable after 12 weeks of follow-up, and the SVR12 rate was 97.3% (95% confidence interval: 95.4%-99.3%). Among them, 97.4% of genotype 1b, 96.4% of genotype 2a, and 100% of those with undetected genotype achieved SVR12. The SVR12 rates in patients with chronic hepatitis C, compensated and decompensated liver cirrhosis were 98.1%, 98.6% and 93.8%, respectively. An improvement in alanine aminotransferase, aspartate aminotransferase and other liver biochemical indicators accompanied with virological clearance and reduced liver stiffness measurement was observed in patients with compensated cirrhosis, with statistically significant difference. There was no significant abnormality in renal function before and after treatment. The most common adverse reactions were fatigue, headache, epigastric discomfort and mild diarrhea. The overall adverse reactions were mild. One patient died of decompensated liver cirrhosis combined with massive upper gastrointestinal bleeding, which was unrelated to antiviral treatment. Four patients discontinued treatment prematurely due to adverse events. Relapse was occurred in four cases, and drug-resistance related mutations were detected in three cases. Conclusion: Sofosbuvir and velpatasvir tablets in Chinese HCV-infected patients with different genotypes, different clinical stages or previously treated with pegylated interferon combined with ribavirin resulted in higher SVR12, indicating that the treatment safety profile is good.

Palitantin derivatives from the Antarctic fungus Geomyces sp. 3-1

Two new polyketides, palitantins B and C (1 and 2), along with one known related compound (+)-palitantin (3) were obtained from the culture of the Antarctic fungus Geomyces sp. 3-1. The structures of the new compounds were elucidated by detailed analysis of HRESIMS, NMR, CD, and ECD data. Compound 3 showed potent PTP1B inhibitory activity with an IC₅₀ value of 7.9 μM (ursolic acid as positive control, IC₅₀ = 8.3 μM).

Leucandioxoles A and B, two 1,3-benzodioxole derivatives from the South China Sea sponge Leucandra sp

Two new 1,3-benzodioxole derivatives, leucandioxoles A and B (1-2), together with two known related compounds (3-4), have been isolated from the South China Sea sponge Leucandra sp. The structures of all compounds were clearly elucidated on the basis of spectroscopic analyses and compared with the literatures. The cytotoxicity against A549, Hep G2, MDA-MB-231, and HeLa cell lines of 1-4 were evaluated. Only compound 1 exhibited moderate activity against MDA-MB-231 cells with the IC₅₀ value of 7.98 ± 0.74 μM.

Dactylospenes A-E, Sesterterpenes from the Marine Sponge Dactylospongia elegans

Chemical investigation on a marine sponge, Dactylospongia elegans, yielded five new γ-oxygenated butenolide sesterterpene derivatives, dactylospenes A–E (1–5), as well as two known biosynthetically related compounds, luffariellolide (6) and furospinosulin B (7). The structures of these compounds were elucidated on the basis of their spectroscopic data, experimental and calculated electronic circular dichroism (ECD) analysis, as well as comparison of the NMR data with those of known analogs. These metabolites are the first γ-oxygenated butenolide sesterterpenes to be reported from this genus. These compounds were evaluated in antimicrobial, anti-inflammatory, and cytotoxic assays. Only compounds 1, 3, and 6 exhibited moderate cytotoxicity against DU145, SW1990, Huh7, and PANC-1 cancer cell lines with IC₅₀ values in the range of 2.11–13.35 μM. Furthermore, compound 2, without cytotoxicity, exhibited significant inhibitory effects (inhibitory rate 77.5%) on nitric oxide production induced by lipopolysaccharide at 10 μM.

[Application and efficacy of the adjustment on left ventricular electrical delay and the distance between right and left ventricular pacing polar in optimizing the left ventricular pacing polar]

Objective: To investigate the application and efficacy of left ventricular (LV) electrical delay (LVED) and the distance of right ventricular(RV) pacing polar to LV(DRLV) in optimizing LV pacing polar. Methods: Heart failure (HF) patients who implanted cardiac resynchronization therapy (CRT) device with a LV quadripolar lead from January 2014 to January 2018 at General Hospital of Northern Theater Command were enrolled in the study. Measurements of LVED and DRLV of each polar of the lead were performed in patients with HF who underwent CRT with LV quadripolar lead. The principle in turn for polar selecting used for clinical LV pacing was the pacing polar: (1)without phrenic nerve stimulation(PNS); (2)with appropriate capture threshold; (3)not located in apical; (4)with maximal LVED; (5)with maximal DRLV. The LV pacing polar was selected for CRT according to the procedure. The distribution of target veins implanted with LV quadripolar lead were calculated. The percentage of biventricular pacing at 6-month follow-up was recorded. The following indexes were compared before and 6-month after surgery, including QRS duration, LV end-systolic volume(LVESV), LV ejection fraction(LVEF), LV end-diastolic dimension(LVEDD), 6 minute walking distance(6MWD), New York Heart Association(NYHA) class. The efficacy and echocardiographic efficacy of CRT was evaluated. Results: There were twenty-nine HF patients enrolled. The mean age of enrolled patients was(61.7±7.6)years old, nineteen (66%)of them were male. There were seventeen(59%) patients diagnosed as dilated cardiomyopathy and twelve(41%) patients as ischemic cardiomyopathy. All patients were successfully implanted with LV quadripolar lead into target veins, and all four pacing sites were also in target veins. Target veins were located in lateral veins in 15 patients (52%), anterior veins in 2 patients (7%), posterior veins in 11 patients (38%), and lateral branches of great cardiac veins in 1 patient (3%). After 6-month of follow-up, the percentage of biventricular pacing was greater than 95%.There were nineteen(66%) patients optimized LV pacing polar by the largest LVED and four (14%) patients by the DRLV. Of the 29 patients, 5(17%) patients used D1 as the pacing polar, 5(17%) patients used M2 as the pacing polar, 7(24%) patients used M3 as the pacing polar, and 12(41%) patients used P4 as the pacing polar. The pacing polars (D1, M2) of traditional bipolar lead were used in 10(34%) patients, and the LV quadripolar lead specific pacing polars (M3, P4) were used in 19(66%) patients.Compared to a LV quadripolar lead, the LV pacing polar (M3, P4) selected in 19(66%) patients were not achievable with the traditional LV bipolar lead (D1, M2). Preoperative QRS duration, LVESV, LVEF, LVEDD, 6MWD and NYHA class were (171±24)ms, (231±79)ml, (28±5)%, (74±11)mm, (294±103)m, (3.2±1.0)class and the postoperative 6-month were (130±12)ms, (158±73)ml, (36±10)%, (66±12)mm, (371±86)m, (1.9±0.5)class. These indexes were significantly improved after 6 months operation(P<0.001). 97% and 83% patients were responders of CRT as assessed by 6-month efficacy and echocardiographic efficacy. Conclusion: The maximal LVED and DRLV can be used to select LV pacing polar with a high rate of CRT response rate.

Pagoamide A, a Cyclic Depsipeptide Isolated from a Cultured Marine Chlorophyte, Derbesia sp., Using MS/MS-Based Molecular Networking

A thiazole-containing cyclic depsipeptide with 11 amino acid residues, named pagoamide A (1), was isolated from laboratory cultures of a marine Chlorophyte, Derbesia sp. This green algal sample was collected from America Samoa, and pagoamide A was isolated using guidance by MS/MS-based molecular networking. Cultures were grown in a light- and temperature-controlled environment and harvested after several months of growth. The planar structure of pagoamide A (1) was characterized by detailed 1D and 2D NMR experiments along with MS and UV analysis. The absolute configurations of its amino acid residues were determined by advanced Marfey's analysis following chemical hydrolysis and hydrazinolysis reactions. Two of the residues in pagoamide A (1), phenylalanine and serine, each occurred twice in the molecule, once in the d- and once in the l-configuration. The biosynthetic origin of pagoamide A (1) was considered in light of other natural products investigations with coenocytic green algae.

An in silico pipeline for subject-specific hemodynamics analysis in liver surgery planning

The progresses in fast simulations of the hepatic flow in subject-specific vascular tree have created new toolkits for pre-surgical planning. The aim of this short communication is to introduce a computational pipeline that integrates several recently developed in silico liver models and algorithms. Firstly, a semi-automatic segmentation pipeline is used to digitise hepatic vessels. Then, a constructive constraint optimisation (CCO) algorithm is used to extend the digitised vascular tree, and also to compute the blood pressure and flow velocity in the tree. Couinaud segments are simulated from the diffusion zones of the portal venous tree. The constructed surgical planning model is then deployed cross-platform for use in various scenarios.

Eutypellacytosporins A-D, Meroterpenoids from the Arctic Fungus Eutypella sp. D-1

The Arctic fungus Eutypella sp. D-1, previously found to produce a variety of cytotoxic cyclopropyl-fused and cyclobutyl-fused pimarane diterpenoids when grown in the defined medium, was induced to produce unusual metabolites by growing on solid rice medium. A chemical investigation on the rice medium extract led to the isolation of four new meroterpenoids, eutypellacytosporins A-D (1-4), along with the known biogenetically related compound cytosporin D (5). The structures of the new compounds were elucidated by their detailed spectroscopic analysis and modified Mosher's method. Compounds 1-4 may be formed by the 12,32-ester linkage of two moieties, cytosporin D (5) and decipienolide A or B. All isolated compounds, except 5, showed weak cytotoxicity against DU145, SW1990, Huh7, and PANC-1 cell lines with IC₅₀ values ranging from 4.9 to 17.1 μM.

Bioactive metabolites from the Arctic fungus Nectria sp. B-13

Two new cyclohexanone derivatives, nectriatones A-B (1-2), and one new natural product, nectriatone C (3), together with three known phenolic sesquiterpene derivatives (4-6), were isolated from the culture of Nectria sp. B-13 obtained from high-latitude soil of the Arctic. The structures of all compounds were unambiguously elucidated by extensive spectroscopic analysis, as well as by comparison with the literature. These compounds were evaluated in cytotoxic and antibacterial activities. Compounds 1-6 showed cytotoxicities against SW1990, HCT-116, MCF-7, and K562 cells, with IC₅₀ values in the range of 0.43 to 42.64 μM. Only compound 4 exhibited antibacterial activity against Escherichisa coli, Bacillus subtilis, and Staphylococcus aureus (MIC 4.0, 2.0, and 4.0 μg/ml, respectively).

Cytotoxic Microcolin Lipopeptides from the Marine Cyanobacterium Moorea producens

Nine new linear lipopeptides, microcolins E-M (1-9), together with four known related compounds, microcolins A-D (10-13), were isolated from the marine cyanobacterium Moorea producens using bioassay-guided and LC-MS/MS molecular networking approaches. Catalytic hydrogenation of microcolins A-D (10-13) yielded two known compounds, 3,4-dihydromicrocolins A and B (14, 15), and two new derivatives, 3,4-dihydromicrocolins C and D (16, 17), respectively. The structures of these new compounds were determined by a combination of spectroscopic and advanced Marfey's analysis. Structurally unusual amino acid units, 4-methyl-2-(methylamino)pent-3-enoic (Mpe) acid and 2-amino-4-methylhexanoic acid (N-Me-homoisoleucine), in compounds 1-3 and 8, respectively, are rare residues in naturally occurring peptides. These metabolites showed significant cytotoxic activity against H-460 human lung cancer cells with IC₅₀ values ranging from 6 nM to 5.0 μM. The variations in structure and attendant biological activities provided fresh insights concerning structure-activity relationships for the microcolin class of lipopeptides.

Cytotoxic meroterpenoids from the marine sponge Dactylospongia elegans

Three new sesquiterpene quinones/hydroquinones, 20-demethoxy-20-isopentylaminodactyloquinone D (1), 20-demethoxy-20-isobutylaminodactyloquinone D (2), and 19-methoxy-dictyoceratin-A (3), and five known related compounds (4-8) were isolated from the marine sponge Dactylospongia elegans. Their structures were elucidated by spectroscopic analysis, ECD calculation, single-crystal X-ray diffraction, and comparison with the literature. Compounds 3 and 5-8 exhibited activities against the human cancer cell lines DU145, SW1990, Huh7, and PANC-1 with IC₅₀ values ranging from 2.33 to 37.85 μM.

Furanone derivative and sesquiterpene from Antarctic marine-derived fungus Penicillium sp. S-1-18

A new furanone derivative, butanolide A (1), and a new sesquiterpene, guignarderemophilane F (2), together with six known compounds, were isolated from the fungus Penicillium sp. S-1-18 derived from Antarctic marine. The new structures were determined by spectroscopic studies such as 1D- and 2D-NMR and MS analyses. The absolute configuration of 1 was determined by the modified Mosher's method, while the absolute configuration of 2 was determined by calculated ECD spectroscopy. The isolated secondary metabolites were evaluated for their protein tyrosine phosphatase 1B (PTP1B) inhibitory activity. Compound 1 showed moderate inhibitory activity against PTP1B with IC₅₀ value of 27.4 μM.

[Mediating effect of work engagement between job stress and depressive symptoms in State Grid employees]

Objective: To explore the relationship between job stress, work engagement and depressive symptoms of State Grid workers, and to analyze the mediating effect of work engagement between job stress and depressive symptoms. Methods: A cross-sectional survey was conducted to investigate 845 employees from a State Grid company, using the brief job stress questionnaire, the Patient Health Questionnaire (PHQ-9) and 9-item Utrecht Work Engagement Scale (UWES-9) in March 2017. Results: The average score of work engagement was 4.49±1.42, the mean value of job stress was 1.15±0.33, the average score of depressive symptoms was 6.44±4.30, and the positive rate of depressive symptoms was 66.9%.There was a negative correlation between work engagement with both job stress and depressive symptoms (r=-0.193, -0.397, both P<0.01) , and job stress was positively correlated with depressive symptoms (r=0.260, P<0.01) . The relationship between job stress and depressive symptoms was partly mediated by work engagement, and the mediating effect accounted for 27.2% of the total effect. Conclusion: The work engagement of State Grid staff acts as the mediator between job stress and depressive symptoms, alleviating the depressive symptoms caused by job stress.

A CT-image based pig atlas model and its potential applications in the meat industry

In this communication we present a novel pig atlas model which is represented by a parametric linear Lagrange or cubic Hermite mesh. The model is developed from data points digitized from a 3D pig CT image. In total 84 muscles and 121 bones are included in the atlas, representing the tissue structures most relevant to the industry. We discuss its potential applications in virtual meat cuts and statistical shape analysis for pig breeding and genetics companies.

Libertellenones O-S and Eutypellenones A and B, Pimarane Diterpene Derivatives from the Arctic Fungus Eutypella sp. D-1

Seven new pimarane-type diterpene derivatives, libertellenones O-S (1-5) and eutypellenones A and B (6 and 7), together with two known compounds (8 and 9), were isolated from the culture of Eutypella sp. D-1 obtained from high-latitude soil of the Arctic. Their structures were elucidated from spectroscopic data, as well as experimental and calculated electronic circular dichroism (ECD) analysis. Structurally, compounds 1-5 possess a cyclopropyl-fused pimarane diterpene moiety, whereas compounds 6 and 7 share an unusual cyclobutyl-fused pimarane diterpene skeleton. Compounds 1-9 exhibited cytotoxicities against HeLa, MCF-7, HCT-116, PANC-1, and SW1990 cells, with IC₅₀ values in the range of 0.3 to 29.4 μM. Compounds 6 and 7 could dose-dependently inhibit the activity of NF-κB and exhibited significantly inhibitory effects on nitric oxide production induced by lipopolysaccharide.

Biotransformation of total coumarins of Radix Glehniae by Lecanicillium attenuatum W-1-9

The biotransformation of total coumarins of Radix Glehniae by Lecanicillium attenuatum W-1-9 yielded three new products, lecaniside A (1), lecaniside B (2), and lecaniside C (3). The chemical structures of these metabolites were elucidated based on extensive spectral data, including 2D NMR and HRMS. The hydrogenation, dealkylation, glycosylation, and O-methylation reactions of these metabolites were observed in the present study. In the in vitro assays, compound 1 displayed a little PTP1B inhibitory activity.

[Heart rate control in chronic heart failure patients received cardiovascular implantable electronic device therapy: effects of optimized medication]

Objective: To investigate the heart rate control situation of chronic heart failure (CHF) patients who received cardiovascular implantable electronic device (CIED) therapy, and to assess the heart rate control efficacy by optimized medication adjustment. Methods: We performed a perspective study in heart failure with reduced left ventricular ejection fraction (HFrEF) patients who received CIED according to guideline recommendations, patients were enrolled from January 2012 to January 2017. Resting heart rate (RHR) recorded by electrocardiogram after 10 minutes' rest and medication usage within 1 month were recorded at baseline. RHR less than 70 beats per minute (bpm) was regarded as well controlled. β-receptor blockers and (or) ivabradine would be added in patients whose RHR were over 70 bpm. RHR after optimized medication adjustment was recorded during follow-up period. Results: One hundred and fifty patients were included in this study with average RHR (80.6±11.9) bpm. RHR was<70 bpm in 27.3% (41/150) patients at baseline and β-receptor blockers was underused in 80.7% patients (88/109) whose RHR was>70 bpm. The overall RHR decreased to (73.1±10.4) bpm and percent of patients with RHR<70 bpm increased to 70.0% (105/150) after up-titration of β-receptor blockers compared to baseline (χ²=52.958, P<0.001). Ivabradine was added in the rest 45 patients and RHR was<70 bpm in 43 out of 45 patients after ivabradine use. The overall RHR decreased to (67.1±2.7) bpm and percent of RHR<70 bpm significantly increased to 98.7% (148/150) (χ²=44.504, P<0.001 vs. up-titration of β-receptor blockers only). Conclusion: RHR in CHF patients who received CIED therapy is not ideally controlled in this patient cohort, individual up-titration ofβ-receptor blockers and ivabradine use may help to optimize RHR in these patients.

[Clinical efficacy of enhanced recovery after surgery in atrial caval shunting for type Ⅱ Budd-Chiari syndrome]

Objective: To investigate the clinical efficacy of enhanced recovery after surgery(ERAS) in atrial caval shunting (ACS) for type Ⅱ Budd-Chiari syndrome(BCS). Methods: The clinical data of patients underwent ACS for type Ⅱ BCS in the Henan Province People's Hospital from January 2014 to June 2016 were prospectively analyzed.Randomized and single-blind, controlled study was performed among the patients, and all of them underwent ACS and were divided into control group (patients underwent traditional perioperative management) and ERAS group (patients underwent ERAS perioperative management) based on a random number table.Operational and postoperative data, levels of inflammatory cytokines, stress state evaluation and postoperative complications were observed.The comparison between the two groups was evaluated with an independent sample t test.The trend analyses for variables were done using repeated measures ANOVA.The count data were analyzed using the chi-square test or Fisher exact. Results: Eighty-two patients were screened for eligibility, and allocated into the control group (40 patients) and the ERAS group (42 patients). All patients underwent ACS successfully with no death.Comparison of intraoperative status: operation time, volume of intraoperative blood and number of patients receiving blood transfusion were (211.0±12.9) minutes vs. (207.7±10.7) minutes, (167.5±28.3) ml vs. (165.0±28.4) ml and 3 cases vs. 1 case between the control group and the ERAS group, respectively, showing no difference between the two groups (t=0.90, 0.29, χ²=0.32, all P>0.05). Comparison of postoperative status: time of gastric tube removal, time of catheter removal, time of chest tube, time to flatus, time of food intake, duration of postoperative infusion, duration of postoperative hospital stay and numeric rating scale were (3.7±0.5)days vs. (0.0±0.0)days, (2.3±0.7)days vs. (1.4±0.5)days, (3.7±0.7)days vs. (2.3±0.5)days, (75.2±3.8)hours vs. (46.6±4.2)hours, (75.7±4.7)hours vs. (21.4±2.1)hours, (10.0±1.0)days vs. (5.8±0.9)days, (11.4±1.0)days vs. (7.8±0.6)days, 2.9±0.4 vs. 1.9±0.6 between the control group and the ERAS group, respectively, with statistically differences (t=35.03, 4.36, 8.10, 22.89, 47.78, 14.75, 14.22, 6.13, all P<0.05). Stress state evaluation: the levels of IR were (2.7±0.1) vs.(2.7±0.1), (8.8±0.7) vs. (5.2±0.3), (11.0±0.5) vs. (7.3±0.5), (4.9±0.2) vs. (3.9±0.1), and the levels of C-reaction protein were (14.6±1.3)mg/L vs.(14.6±1.1) mg/L, (101.2±13.6) mg/L vs. (89.5±6.9) mg/L, (62.7±8.6) mg/L vs. (56.4±8.4) mg/L, (46.4±6.7) mg/L vs. (40.0±5.6) mg/L from pre-operation to postoperative day 1, 3 and 5 between the control group and the ERAS group, respectively, with statistically significant differences in changing trends(F=136.61, 4.97, both P<0.05). Comparisons of levels of inflammatory cytokines: the levels of IL-6 were (43.1±2.7) ng/L vs. (43.6±3.6) ng/L, (135.1±6.4) ng/L vs. (117.4±5.7) ng/L, (145.4±6.7) ng/L vs. (128.5±5.5) ng/L, (93.3±3.7) ng/L vs. (88.0±3.9) ng/L, and the levels of TNF-α were (10.4±0.3)mmol/L vs. (10.4±0.3) mmol/L, (14.4±0.4) mmol/L vs. (12.6±0.4) mmol/L, (15.6±0.4) mmol/L vs. (13.8±0.4) mmol/L, (12.3±0.7) mmol/L vs. (11.4±0.6) mmol/L from pre-operation to postoperative day 1, 3 and 5 between the control group and the ERAS group, respectively, with statistically significant differences in changing trends (F=15.15, 21.45, both P<0.05). Comparison of postoperative complications: incidence of complications was 30.0%(12/40) in the control group and 11.9%(5/42) in the ERAS group, and the numbers of patients with nausea and vomiting, respiratory complications and cardiovascular complications were 4, 3, 5 cases in the control group and 3, 1, 1 case in the ERAS group, respectively, showing statistically differences in the incidence of complications(χ²=4.08, P<0.05). All the 82 patients were followed up for 2 to 22 months (median time, 12 months), no patients received reoperation or re-admitted to the hospital duo to complications. Conclusion: ERAS management in the perioperative period of ACS for BCS is beneficial to postoperative recovery of patients, and can relieve postoperative stress state and inflammatory response, reduce the duration of hospital stay, and incidence of postoperative complications.

Sesquiterpene Quinones/Hydroquinones from the Marine Sponge Spongia pertusa Esper

Nine new sesquiterpene quinones/hydroquinones (1-7, 10, and 12), three solvent-generated artifacts (8, 9, and 11), and three known compounds, 5-epi-smenospongine (13), smenospongine (14), and smenospongiadine (15), were isolated from the marine sponge Spongia pertusa Esper. The planar structures of the new compounds were elucidated on the basis of spectroscopic analyses. Their absolute configurations were determined by comparison between the calculated and experimental ECD spectra. In the cytotoxicity bioassay, compounds 13-15 exhibited activities against the human cancer cell lines U937, HeLa, and HepG2, with most potent cytotoxicities to U937 cells with IC₅₀ values of 2.8, 1.5, and 0.6 μM, respectively. In addition, compound 6 displayed CDK-2 affinity with a K_d value of 4.8 μM in a surface plasmon resonance assay.

[Establishment and application of a digital workflow in the treatment of condylar osteochondroma and secondary dentofacial deformities using image-guided endoscopic navigation combined with orthognathic surgery]

Objective: To establish a digital workflow in the treatment of mandibular condylar osteochondroma with secondary dentofacial deformities using navigation and endoscope combined with orthognathic surgery. Methods: Thirty-six patients with unilateral condylar osteochondroma were analyzed retrospectively. Preoperative planning and simulation were carried out on the digital three-dimansional (3D) model in all patients. With the aid of image-guided endoscopic navigation, osteochondroma resection and condylectomy were accurately performed. Secondary dentofacial deformities were simultaneously corrected using orthognathic surgery. All patients were followed up regularly and received postoperative CT scans. The preoperative simulated model and the postoperative actual model were matched using ProPlan CMF 2.0 software. Four corresponding points were marked in the virtual and actual ostectomy plane, respectively. The intersections of mandibular sigmoid notch and posterior ramusrim with condylectomy plane were marked as the anterior point and the posterior point, respectively. The perpendicular bisector of the line from the anterior point to the posterior point was intersected with the lateral and medial margin of condylectomy plane to form the lateral point and the medial point, respectively. The straight-line distances between the corresponding points in the virtual and actual ostectomy plane were respectively measured to analyze the ostectomy discrepancy. Results: All of 36 patients obtained satisfactory clinical effects. Facial symmetry and morphology were greatly improved. Postoperative CT showed that condylar tumors were completely removed. The preoperative simulated model and the postoperative actual model were matched. The average discrepancy between the planned and actual surgical resection was minimal on the anterior points ([0.24 ± 0.17] mm) and the mean error was maximal on the posterior points ([3.86±1.03] mm). The patients showed no signs of tumor recurrence in the 6 to 12 months of follow-up. Conclusions: Endoscope-assisted and navigation-guided tumor resection and condylectomy combined with simultaneous orthognathic surgery has satisfactory clinical effects in the treatment of condylar osteochondroma and secondary dentofacial deformities. The digital management workflow reported in this paper provides us a valuable option for this potentially complicated procedure.

[A multi-center study on the long-term mortality and related risk factors in patients with chronic heart failure receiving resynchronization therapy]

Objective: To analyze long-term mortality and patients characteristics of cardiac resynchronization therapy (CRT) for patients with chronic heart failure. Methods: In-patients with chronic heart failure who received CRT in the three medical centers(Bethune International Peace Hospital, General Hospital of Shenyang Military Command of Chinese People's Liberation Army, and 251 Hospital of People's Liberation Army)from March 2001 to June 2013 were included.Mortality and related causes, echocardiographic parameters were analyzed. Results: A total of 200 patients were treated with CRT therapy (154 males, mean age (60.57±11.75) years), 59 cases suffered from ischemic cardiomyopathy (ICM), patients were followed up from 0.5 to 12 years.The all-cause mortality rate was 25.50% (51/200), 20 out of 59 (33.90%) ICM patients died, as compared with 31 deaths out of 141 (21.98%) in non-ischemic cardiomyopath (NICM) patients.Thirty-six patients died due to cardiac death (70.59%), in which sudden death occurred in 21 patients (41.18%). Non-cardiac death occurred in 13 patients (25.49%), two patients died due to unknown reasons (3.92%). Incidence of cardiac death was significantly higher than non-cardiac death (P<0.01). The main cause for cardiac death was NICM (28/36, 77.78%), while the main cause of non-cardiac death was ICM (11/13, 84.62%, P<0.01). Patients died due to cardiac death were younger (P<0.01) and had larger left atrial end-diastolic diameter (LAEDD) and left ventricular end-diastolic diameter (LVEDD) (P<0.01), lower left ventricular ejection fraction (LVEF)(P<0.05), higher pulmonary artery pressure(P<0.05) compared to patients with non-cardiac death.One hundred and fifty-two cases received CRT-P and 48 cases received CRT-D, there were no significant differences in gender, the course of heart failure, serum creatinine levels, pre-operative and post-operative QRS duration and so on between the CRT-P and CRT-D groups(all P>0.05). Eleven out of the 48 cases with CRT-D died during the following-up (21.57%) , while 40 out of 152 cases with CRT-P died (78.43%) during the following-up(χ²=3.13, P<0.01). The proportional mortality rate in cause of death in patients with CRT-D was non-cardiac while in those with CRT-P was cardiac (χ²=2.66, P<0.01), sudden death rate was also significantly higher in CRT-P group than in CRT-D group (χ²=2.16, P<0.01). By using single- and multiple-factor Cox regression analysis, age, disease course, pre-operation QRS duration and NYHA classification were predictors of cardiac death(all P<0.05). Conclusions: The all-cause mortality of CRT is 25.50% in this patient cohort, mortality rate was higher in ICM patients than in NICM patients.Sudden cardiac death rate was the highest mortality reason.The mortality rate of patients with CRT-P was significantly higher than in patients with CRT-D.In comparison with patients of non-cardiac death, patients of cardiac death had larger left atrium and left ventricle and worse heart function before CRT implantation.

Three new aaptamine derivatives from the South China Sea sponge Aaptos aaptos

Three new aaptamine derivatives (1-3), together with six known related compounds (4-9), have been isolated from the South China Sea sponge Aaptos aaptos. The structures of all compounds were unambiguously elucidated on the basis of spectroscopic analyses. Compounds 1, 4, 5, 7, and 9 showed cytotoxic activities against HeLa, K562, MCF-7, and U937 cell lines with IC50 values in the range of 0.90-12.32 μM.

Suppression of β Relaxation in Vapor-Deposited Ultrastable Glasses

Glassy materials display numerous important properties which relate to the presence and intensity of the secondary (β) relaxations that dominate the dynamics below the glass transition temperature. However, experimental protocols such as annealing allow little control over the β relaxation for most glasses. Here we report on the β relaxation of toluene in highly stable glasses prepared by physical vapor deposition. At conditions that generate the highest kinetic stability, about 70% of the β relaxation intensity is suppressed, indicating the proximity of this state to the long-sought "ideal glass." While preparing such a state via deposition takes less than an hour, it would require ~3500 years of annealing an ordinary glass to obtain similarly suppressed dynamics.

Unified Criterion for Temperature-Induced and Strain-Driven Glass Transitions in Metallic Glass

In a model metallic glass, we study the relaxation dynamics in both the linear and the nonlinear response regimes by numerical simulations of dynamical mechanical spectroscopy and analyze the atomic displacement statistics. We find that the primary (α) relaxation always takes place when the most probable atomic displacement reaches a critical fraction (~20%) of the average interatomic distance, irrespective of whether the relaxation is induced by temperature (linear response) or by mechanical strain (nonlinear response). Such a unified scenario, analogous to the well-known Lindemann criterion for crystal melting, provides insight into the structural origin of the strain-induced glass-liquid transition.

New Furan and Cyclopentenone Derivatives from the Sponge-Associated Fungus Hypocrea Koningii PF04

Two new furan derivatives, hypofurans A and B (1 and 2), and three new cyclopentenone derivatives, hypocrenones A-C (3-5), along with seven known compounds (6-12), were isolated from a marine fungus Hypocrea koningii PF04 associated with the sponge Phakellia fusca. Among them, compounds 10 and 11 were obtained for the first time as natural products. The planar structures of compounds 1-5 were elucidated by analysis of their spectroscopic data. Meanwhile, the absolute configuration of 1 was determined as 2R,3R by the comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. All the isolates were evaluated for their antibacterial and antioxidant activity. Compounds 1, 10, and 12 all showed modest antibacterial activity against Staphylococcus aureus ATCC25923 (MIC, 32 μg/mL). In addition, compounds 1, 10 and 11 exhibited moderate DPPH radical scavenging capacity with IC50 values of 27.4, 16.8, and 61.7 µg/mL, respectively.

Cytotoxic Bryostatin Derivatives from the South China Sea Bryozoan Bugula neritina

Four new macrocyclic lactones, bryostatin 21 (1) and 9-O-methylbryostatins 4, 16, and 17 (2-4), together with three known related compounds, bryostatins 4, 16, and 17 (5-7), have been isolated from an extract of the South China Sea bryozoan Bugula neritina. The structures of all compounds were unambiguously elucidated using detailed spectroscopic analysis. Structurally, the presence of a single methyl group at C-18 in compound 1 has not been observed before for known bryostatins. The isolated macrolides exhibited inhibitory effects against a small panel of human cancer cell lines.

(±)-Quassidines I and J, two pairs of cytotoxic bis-β-carboline alkaloid enantiomers from Picrasma quassioides

(±)-Quassidines I (1) and J (2), two pairs of new bis-β-carboline alkaloid enantiomers, were isolated from the stems of Picrasma quassioides. Their structures were determined by the analysis of spectroscopic data, including HRESIMS and 2D NMR, and confirmed by single-crystal X-ray diffraction analysis. The racemic mixtures of 1 and 2 were resolved into two pairs of enantiomers, (+)-S-1a and (-)-R-1b and (+)-S-2a and (-)-R-2b, by HPLC using a chiral Daicel IB-3 column, respectively, which represents the first successful example to resolve bis-β-carboline racemic mixtures. The absolute configurations of the two pairs of enantiomers were determined by comparison between the calculated and experimental ECD spectra. The cytotoxicity evaluation revealed that (+)-S-1a and (+)-S-2a showed more potent cytotoxicity against human cervical HeLa and gastric MKN-28 cancer cell lines with IC50 values of 4.03-6.30 μM than their enantiomers with IC50 values of 9.64-12.3 μM; however, the two (+)-S-quassidines showed similar activities to their enantiomers against the mouse melanoma B-16 cancer cell line.

Computer-assisted surgical planning and intraoperative navigation in the treatment of condylar osteochondroma

Mandibular condylar osteochondroma (OC) results in asymmetric prognathism with facial morphology and functional disturbances. The aim of this study was to explore the feasibility of computer-assisted surgical planning combined with intraoperative navigation in the treatment of condylar OC. Five patients with mandibular condylar OC were enrolled in this study. Surgical planning and simulation was performed based on a computed tomography reconstruction model using SurgiCase software. Under the guidance of navigation, a condylar OC resection and conservative condylectomy was carried out via intraoral approach. Simultaneous orthognathic surgery was used to correct the facial asymmetry and malocclusion. All patients healed uneventfully. No facial nerve injury or salivary fistula occurred. Facial symmetry and morphology were greatly improved and stable occlusion was obtained in all cases. Good matching between preoperative planning and postoperative results was achieved. Patients showed no signs of recurrence or temporomandibular joint ankylosis during follow-up of 12-30 months. Computer-assisted surgical planning and intraoperative navigation is a valuable option in the treatment of mandibular condylar OC.

Cytotoxic aaptamine derivatives from the South China Sea sponge Aaptos aaptos

Nine new aaptamine derivatives (1-9), together with three known related compounds (10-12), have been isolated from the South China Sea sponge Aaptos aaptos. The structures of all compounds were unambiguously elucidated on the basis of spectroscopic analyses. Structurally, compound 1 possesses a piperidinyl group fused to a demethyl(oxy)aaptamine moiety, whereas compounds 3-6 share an imidazole-fused 1H-benzo[de][1,6]naphthyridin-2(4H)-one skeleton. The cytotoxic activities of the compounds were evaluated against various human cancer cell lines, and compounds 2, 8, 11, and 12 showed potent cytotoxicities against HL60, K562, MCF-7, KB, HepG2, and HT-29 cells, with IC50 values in the range of 0.03 to 8.5 μM.

Dysideanones A-C, unusual sesquiterpene quinones from the South China Sea sponge Dysidea avara

Dysideanones A-C (1-3), three unusual sesquiterpene quinones with unprecedented carbon skeletons, were isolated from the South China Sea sponge Dysidea avara. Their structures including absolute configurations were determined by a combination of spectroscopic analyses and calculated ECD spectra. Within the sesquiterpene quinone structures, dysideanones A (1) and B (2) share an unprecedented 6/6/6/6-fused tetracyclic carbon skeleton, while dysideanone C (3) possesses an unusual 6/6/5/6-fused tetracyclic core. Dysideanone B (2) showed cytotoxicity against two human cancer cell lines, HeLa and HepG2, with IC50 values of 7.1 and 9.4 μM, respectively.

Dysidaminones A–M, cytotoxic and NF-κB inhibitory sesquiterpene aminoquinones from the South China Sea sponge Dysidea fragilis

Structural determination, absolute configuration assignments, and biological activities of new sesquiterpene aminoquinones from Dysidea fragilis.

Endoscope-assisted conservative condylectomy in the treatment of condylar osteochondroma through an intraoral approach

Mandibular condylar osteochondroma (OC) can result in morphological and functional disturbances, including facial asymmetry and temporomandibular joint (TMJ) dysfunction. The aim of this study was to explore the feasibility of endoscope-assisted tumour resection and conservative condylectomy via an intraoral approach. Seven patients with condylar OC were enrolled in this study. Endoscope-assisted tumour resection and conservative condylectomy were achieved intraorally, and no conventional extraoral incision was needed. Direct vision of the magnified and illuminated operative field was realized with the assistance of an endoscope. No facial nerve injury or salivary fistula occurred in any patient. Stable occlusion was realized through postoperative orthodontic treatment. The patients showed no signs of tumour recurrence or TMJ ankylosis during follow-up (range 18-43 months). Endoscope-assisted condylar OC resection and conservative condylectomy via intraoral approach offers great advantages with no significant complications compared with conventional extraoral incisions. The endoscope provides us with a valuable treatment option for this potentially complicated procedure.

Correlation between β relaxation and self-diffusion of the smallest constituting atoms in metallic glasses

In multicomponent metallic glasses, we demonstrate that diffusion and secondary (β) relaxation are closely related. The diffusion motion of the smallest constituting atoms takes place within the temperature and time regimes where the β relaxations are activated, and, in particular, the two processes have similar activation energies. We suggest cooperative stringlike atomic motion plays an important role in both processes. This finding provides additional insights into the structural origin of the β relaxations as well as the mechanisms of diffusions in metallic glasses.

Woodylides A-C, new cytotoxic linear polyketides from the South China Sea sponge Plakortis simplex

Three new polyketides, woodylides A–C (1–3), were isolated from the ethanol extract of the South China Sea sponge Plakortis simplex. The structures were elucidated by spectroscopic data (IR, 1D and 2D NMR, and HRESIMS). The absolute configurations at C-3 of 1 and 3 were determined by the modified Mosher’s method. Antifungal, cytotoxic, and PTP1B inhibitory activities of these polyketides were evaluated. Compounds 1 and 3 showed antifungal activity against fungi Cryptococcus neoformans with IC₅₀ values of 3.67 and 10.85 µg/mL, respectively. In the cytotoxicity test, compound 1 exhibited a moderate effect against the HeLa cell line with an IC₅₀ value of 11.2 µg/mL, and compound 3 showed cytotoxic activity against the HCT-116 human colon tumor cell line and PTP1B inhibitory activity with IC₅₀ values of 9.4 and 4.7 µg/mL, respectively.

Tensile plasticity in metallic glasses with pronounced β relaxations

Metallic glasses are commonly brittle, as they generally fail catastrophically under uniaxial tension. Here we show pronounced macroscopic tensile plasticity achieved in a La-based metallic glass which possesses strong β relaxations and nanoscale heterogeneous structures. We demonstrate that the β relaxation is closely correlated with the activation of the structural units of plastic deformations and global plasticity, and the transition from brittle to ductile in tension and the activation of the β relaxations follow a similar time-temperature scaling relationship. The results have implications for understanding the mechanisms of plastic deformation and structural origin of β relaxations as well as for solving the brittleness in metallic glasses.