A log odds of positive lymph nodes-based predictive model effectively forecasts prognosis and guides postoperative adjuvant chemotherapy duration in stage III colon cancer: a multi-center retrospective cohort study.

BACKGROUND: The log odds of positive lymph nodes (LODDS) was considered a superior staging system to N stage in colon cancer, yet its value in determining the optimal duration of adjuvant chemotherapy for stage III colon cancer patients has not been evaluated. This study aims to assess the prognostic value of a model that combines LODDS with clinicopathological information for stage III colon cancer patients and aims to stratify these patients using the model, identifying individuals who could benefit from varying durations of adjuvant chemotherapy. METHOD: A total of 663 consecutive patients diagnosed with stage III colon cancer, who underwent colon tumor resection between November 2007 and June 2020 at Sun Yat-sen University Cancer Center and Longyan First Affiliated Hospital of Fujian Medical University, were enrolled in this study. Survival outcomes were analyzed using Kaplan-Meier, Cox regression. Nomograms were developed to forecast patient DFS, with the Area Under the Curve (AUC) values of time-dependent Receiver Operating Characteristic (timeROC) and calibration plots utilized to assess the accuracy and reliability of the nomograms. RESULTS: Multivariate analysis revealed that perineural invasion (HR = 1.776, 95% CI: 1.052-3.003, P = 0.032), poor tumor differentiation (HR = 1.638, 95% CI: 1.084-2.475, P = 0.019), and LODDS groupings of 2 and 1 (HR = 1.920, 95% CI: 1.297-2.842, P = 0.001) were independent predictors of disease-free survival (DFS) in the training cohort. Nomograms constructed from LODDS, perineural invasion, and poor tumor differentiation demonstrated robust predictive performance for 3-year and 5-year DFS in both training (3-year AUC = 0.706, 5-year AUC = 0.678) and validation cohorts (3-year AUC = 0.744, 5-year AUC = 0.762). Stratification according to this model showed that patients in the high-risk group derived significant benefit from completing 8 cycles of chemotherapy (training cohort, 82.97% vs 67.17%, P = 0.013; validation cohort, 89.49% vs 63.97%, P = 0.030). CONCLUSION: The prognostic model, integrating LODDS, pathological differentiation, and neural invasion, demonstrates strong predictive accuracy for stage III colon cancer prognosis. Moreover, stratification via this model offers valuable insights into optimal durations of postoperative adjuvant chemotherapy.

Impact of lymph node retrieval on prognosis in elderly and non-elderly patients with T3-4/N+ rectal cancer following neoadjuvant therapy: a retrospective cohort study.

PURPOSE: The optimal number of lymph nodes to be resected in patients with rectal cancer who undergo radical surgery after neoadjuvant therapy remains controversial. This study evaluated the prognostic variances between elderly and non-elderly patients and determined the ideal number of lymph nodes to be removed in these patients. METHODS: The Surveillance, Epidemiology, and End Results (SEER) datasets were used to gather information on 7894 patients diagnosed with stage T3-4/N+ rectal cancer who underwent neoadjuvant therapy from 2010 to 2019. Of these patients, 2787 were elderly and 5107 were non-elderly. A total of 152 patients from the Longyan First Affiliated Hospital of Fujian Medical University were used for external validation. Overall survival (OS) and cancer-specific survival (CSS) were evaluated to determine the optimal quantity of lymph nodes for surgical resection. RESULTS: The study found significant differences in OS and CSS between elderly and non-elderly patients, both before and after adjustment for confounders (P < 0.001). The removal of 14 lymph nodes may be considered a benchmark for patients with stage T3-4/N+ rectal cancer who undergo radical surgery following neoadjuvant therapy, as this number provides a more accurate foundation for the personalized treatment of rectal cancer. External data validated the differences in OS and CSS and supported the 14 lymph nodes as a new benchmark in these patients. CONCLUSION: For patients with T3-4/N+ stage rectal cancer who undergo radical surgery following neoadjuvant therapy, the removal of 14 lymph nodes serves as a cutoff point that distinctly separates patients with a favorable prognosis from those with an unfavorable one.

Conditional survival analysis and real-time prognosis prediction in stage III T3-T4 colon cancer patients after surgical resection: a SEER database analysis.

BACKGROUND: Conditional survival (CS) takes into consideration the duration of survival post-surgery and can provide valuable additional insights. The aim of this study was to investigate the risk factors associated with reduced one-year postoperative conditional survival in patients diagnosed with stage III T3-T4 colon cancer and real-time prognosis prediction. Furthermore, we aim to develop pertinent nomograms and predictive models. METHODS: Clinical data and survival outcomes of patients diagnosed with stage III T3-T4 colon cancer were obtained from the Surveillance, Epidemiology, and End Results (SEER) database, covering the period from 2010 to 2019. Patients were divided into training and validation cohorts at a ratio of 7:3. The training set consisted of a total of 11,386 patients for conditional overall survival (cOS) and 11,800 patients for conditional cancer-specific survival (cCSS), while the validation set comprised 4876 patients for cOS and 5055 patients for cCSS. Univariate and multivariate Cox regression analyses were employed to identify independent risk factors influencing one-year postoperative cOS and cCSS. Subsequently, predictive nomograms for cOS and cCSS at 2-year, 3-year, 4-year, and 5-year intervals were constructed based on the identified prognostic factors. The performance of these nomograms was rigorously assessed through metrics including the concordance index (C-index), calibration curves, and the area under curve (AUC) derived from the receiver operating characteristic (ROC) analysis. Clinical utility was further evaluated using decision curve analysis (DCA). RESULTS: A total of 18,190 patients diagnosed with stage III T3-T4 colon cancer were included in this study. Independent risk factors for one-year postoperative cOS and cCSS included age, pT stage, pN stage, pretreatment carcinoembryonic antigen (CEA) levels, receipt of chemotherapy, perineural invasion (PNI), presence of tumor deposits, the number of harvested lymph nodes, and marital status. Sex and tumor site were significantly associated with one-year postoperative cOS, while radiation therapy was notably associated with one-year postoperative cCSS. In the training cohort, the developed nomogram demonstrated a C-index of 0.701 (95% CI, 0.711-0.691) for predicting one-year postoperative cOS and 0.701 (95% CI, 0.713-0.689) for one-year postoperative cCSS. Following validation, the C-index remained robust at 0.707 (95% CI, 0.721-0.693) for one-year postoperative cOS and 0.700 (95% CI, 0.716-0.684) for one-year postoperative cCSS. ROC and calibration curves provided evidence of the model's stability and reliability. Furthermore, DCA underscored the nomogram's superior clinical utility. CONCLUSIONS: Our study developed nomograms and predictive models for postoperative stage III survival in T3-T4 colon cancer with the aim of accurately estimating conditional survival. Survival bias in our analyses may lead to overestimation of survival outcomes, which may limit the applicability of our findings.

Clustering-Resistant Cu Single Atoms on Porous Au Nanoparticles Supported by TiO2 for Sustainable Photoconversion of CO2 into CH4.

Photocatalysts based on single atoms (SAs) modification can lead to unprecedented reactivity with recent advances. However, the deactivation of SAs-modified photocatalysts remains a critical challenge in the field of photocatalytic CO2 reduction. In this study, we unveil the detrimental effect of CO intermediates on Cu single atoms (Cu-SAs) during photocatalytic CO2 reduction, leading to clustering and deactivation on TiO2. To address this, we developed a novel Cu-SAs anchored on Au porous nanoparticles (CuAu-SAPNPs-TiO2) via a vectored etching approach. This system not only enhances CH4 production with a rate of 748.8 µmol ⋅ g-1 ⋅ h-1 and 93.1 % selectivity but also mitigates Cu-SAs clustering, maintaining stability over 7 days. This sustained high performance, despite the exceptionally high efficiency and selectivity in CH4 production, highlights the CuAu-SAPNPs-TiO2 overarching superior photocatalytic properties. Consequently, this work underscores the potential of tailored SAs-based systems for efficient and durable CO2 reduction by reshaping surface adsorption dynamics and optimizing the thermodynamic behavior of the SAs.

Neoadjuvant Chemotherapy With CAPOX Versus Chemoradiation for Locally Advanced Rectal Cancer With Uninvolved Mesorectal Fascia (CONVERT): Initial Results of a Phase III Trial.

OBJECTIVE: To compare neoadjuvant chemotherapy (nCT) with CAPOX alone versus neoadjuvant chemoradiotherapy (nCRT) with capecitabine in locally advanced rectal cancer (LARC) with uninvolved mesorectal fascia (MRF). BACKGROUND DATA: nCRT is associated with higher surgical complications, worse long-term functional outcomes, and questionable survival benefits. Comparatively, nCT alone seems a promising alternative treatment in lower-risk LARC patients with uninvolved MRF. METHODS: Patients between June 2014 and October 2020 with LARC within 12 cm from the anal verge and uninvolved MRF were randomly assigned to nCT group with 4 cycles of CAPOX (Oxaliplatin 130 mg/m2 IV day 1 and Capecitabine 1000 mg/m2 twice daily for 14 d. Repeat every 3 wk) or nCRT group with Capecitabine 825 mg/m² twice daily administered orally and concurrently with radiation therapy (50 Gy/25 fractions) for 5 days per week. The primary end point is local-regional recurrence-free survival. Here we reported the results of secondary end points: histopathologic response, surgical events, and toxicity. RESULTS: Of the 663 initially enrolled patients, 589 received the allocated treatment (nCT, n=300; nCRT, n=289). Pathologic complete response rate was 11.0% (95% CI, 7.8-15.3%) in the nCT arm and 13.8% (95% CI, 10.1-18.5%) in the nCRT arm ( P =0.33). The downstaging (ypStage 0 to 1) rate was 40.8% (95% CI, 35.1-46.7%) in the nCT arm and 45.6% (95% CI, 39.7-51.7%) in the nCRT arm ( P =0.27). nCT was associated with lower perioperative distant metastases rate (0.7% vs. 3.1%, P =0.03) and preventive ileostomy rate (52.2% vs. 63.6%, P =0.008) compared with nCRT. Four patients in the nCT arm received salvage nCRT because of local disease progression after nCT. Two patients in the nCT arm and 5 in the nCRT arm achieved complete clinical response and were treated with a nonsurgical approach. Similar results were observed in subgroup analysis. CONCLUSIONS: nCT achieved similar pCR and downstaging rates with lower incidence of perioperative distant metastasis and preventive ileostomy compared with nCRT. CAPOX could be an effective alternative to neoadjuvant therapy in LARC with uninvolved MRF. Long-term follow-up is needed to confirm these results.

Progress in diagnosis of bone metastasis of prostate cancer. / å‰åˆ—è ºç™Œéª¨è½¬ç§»è¯Šæ–­çš„ç ”ç©¶è¿›å±•.

The diagnosis of bone metastasis of prostate cancer (PC) is of great significance to the treatment and prognosis of patients with PC.Bone scan is the most commonly used in the early diagnosis of bone metastasis, but its specificity is low and there is a high false positive.In recent years, with the in-depth study of the application of CT, MRI, emission computed tomography (ECT), positron emission computed tomography/computed tomography (PET/CT) and deep learning algorithm-convolutional neural networks (CNN) in the diagnosis of bone metastasis, the combined application of various auxiliary parameters in the diagnosis of bone metastasis has significantly been improved. The therapeutic effect of PC patients with bone metastasis can also be evaluated, which is expected to achieve the treatment of bone metastasis as well as diagnosis. By systematically expounding the research progress of the above-mentioned techniques in the diagnosis of bone metastasis, it can provide clinicians with new methods for the diagnosis of bone metastasis and improve the diagnostic efficiency for bone metastasis.

Conditional survival and recurrence of remnant gastric cancer after surgical resection: A multi-institutional study.

The present study was designed to evaluate the dynamic survival and recurrence of remnant gastric cancer (RGC) after radical resection and to provide a reference for the development of personalized follow-up strategies. A total of 298 patients were analyzed for their 3-year conditional overall survival (COS3), 3-year conditional disease-specific survival (CDSS3), corresponding recurrence and pattern changes, and associated risk factors. The 5-year overall survival (OS) and the 5-year disease-specific survival (DSS) of the entire cohort were 41.2% and 45.8%, respectively. The COS3 and CDDS3 of RGC patients who survived for 5 years were 84.0% and 89.8%, respectively. The conditional survival in patients with unfavorable prognostic characteristics showed greater growth over time than in those with favorable prognostic characteristics (eg, COS3, ≥T3: 46.4%-83.0%, Δ36.6% vs ≤T2: 82.4%-85.7%, Δ3.3%; P < 0.001). Most recurrences (93.5%) occurred in the first 3 years after surgery. The American Joint Committee on Cancer (AJCC) stage was the only factor that affected recurrence. Time-dependent Cox regression showed that for both OS and DSS, after 4 years of survival, the common prognostic factors that were initially judged lost their ability to predict survival (P > 0.05). Time-dependent logistic regression analysis showed that the AJCC stage independently affected recurrence within 2 years after surgery (P < 0.05). A postoperative follow-up model was developed for RGC patients. In conclusion, patients with RGC usually have a high likelihood of death or recurrence within 3 years after radical surgery. We developed a postoperative follow-up model for RGC patients of different stages, which may affect the design of future clinical trials.

Boosted Photoelectrochemical N2 Reduction over Mo2C In Situ Coated with Graphitized Carbon.

Photoelectrochemical N2 reduction reaction (PEC NRR) is a promising method to solve the problems of environmental protection and energy sustainability. However, the strong chemical stability of the N≡N bond and competitive hydrogen evolution reaction (HER) cause the nonideal efficiency of N2 → NH3 conversion in actual operation. For the first time, a Mo2C/C heterostructure was fabricated as a PEC cathode for N2 reduction under environmental conditions. The Mo2C/C heterostructure could effectively decrease the coverage of hydrogen spillover and inhibit the competitive HER, resulting in a desirable selectivity for N2 activation. Meanwhile, the decoration of the C shell further promoted the stability and conductivity of Mo2C. Mo sites of Mo2C were considered as activation centers, which played a dominant role in the final PEC performance. An optimal NH3 yield rate of up to 6.6 µg h-1 mg-1 was achieved with the Mo2C/C heterostructure, which was almost 3 times that with pristine C. The faradic efficiency (FE) of the Mo2C/C heterostructure was 37.2% at 0.2 V (vs Ag/AgCl). This work not only provides an insight into the interplay between the Mo2C/C heterostructure and N2 activation, but also reveals its great potential in NH3 synthesis by a green route.

Safety and feasibility of laparoscopic spleen-preserving No. 10 lymph node dissection for locally advanced upper third gastric cancer: a prospective, multicenter clinical trial.

BACKGROUND: Previous retrospective studies have shown that laparoscopic spleen-preserving D2 total gastrectomy (LSTG) for advanced upper third gastric cancer (AUTGC) is safe. However, all previous studies were underpowered. We therefore conducted a prospective, multicenter study to evaluate the technical safety and feasibility of LSTG for patients with AUTGC. METHODS: Patients diagnosed with AUTGC (cT2-4a, N-/+, M0) underwent LSTG at 19 institutions between September 2016 and October 2017 were included. The number of No. 10 lymph node (LN) dissections, metastasis rates, intraoperative and postoperative complications were investigated. RESULTS: A total of 251 patients were enrolled in the study, and 242 patients were eligible for the per protocol analysis. The average numbers of No. 10 LN dissections and metastases were 2.4 and 0.1, respectively. Eighteen patients (7.4%) had No. 10 LN metastases, and among patients with advanced gastric cancer, the rate of No. 10 LN metastasis was 8.1% (18/223). pN3 status was an independent risk factor for No. 10 LN metastasis. Intraoperative complications occurred in 7 patients, but no patients required conversion to open surgery or splenectomy. The overall postoperative complication rate was 13.6% (33/242). The major complication and mortality rates were 3.3% (8/242) and 0.4% (1/242), respectively. The number of retrieved No. 10 LNs, No. 10 LN metastasis and TNM stage had no significant influence on postoperative complication rates. CONCLUSION: LSTG for AUTGC was safe and effective when performed by very experienced surgeons, this technique could be used in patients who needed splenic hilar lymph node dissection.

Bioactive Molecules from Mangrove Streptomyces qinglanensis 172205.

Five new compounds 15R-17,18-dehydroxantholipin (1), (3E,5E,7E)-3-methyldeca-3,5,7-triene-2,9-dione (2) and qinlactone A-C (3-5) were identified from mangrove Streptomyces qinglanensis 172205 with "genetic dereplication," which deleted the highly expressed secondary metabolite-enterocin biosynthetic gene cluster. The chemical structures were established by spectroscopic methods, and the absolute configurations were determined by electronic circular dichroism (ECD). Compound 1 exhibited strong anti-microbial and antiproliferative bioactivities, while compounds 2-4 showed weak antiproliferative activities.

Identification of a Novel Lincomycin Resistance Mutation Associated with Activation of Antibiotic Production in Streptomyces coelicolor A3(2).

Comparative genome sequencing analysis of a lincomycin-resistant strain of Streptomyces coelicolor A3(2) and the wild-type strain identified a novel mutation conferring a high level of lincomycin resistance. Surprisingly, the new mutation was an in-frame DNA deletion in the genes SCO4597 and SCO4598, resulting in formation of the hybrid gene linR. SCO4597 and SCO4598 encode two histidine kinases, which together with SCO4596, encoding a response regulator, constitute a unique two-component system. Sequence analysis indicated that these three genes and their arrangement patterns are ubiquitous among all Streptomyces genomes sequenced to date, suggesting these genes play important regulatory roles. Gene replacement showed that this mutation was responsible for the high level of lincomycin resistance, the overproduction of the antibiotic actinorhodin, and the enhanced morphological differentiation of this strain. Moreover, heterologous expression of the hybrid gene linR in Escherichia coli conferred resistance to lincomycin in this organism. Introduction of the hybrid gene linR in various Streptomyces strains by gene engineering technology may widely activate and/or enhance antibiotic production.

IL-8 interacts with metadherin promoting proliferation and migration in gastric cancer.

It has been reported that IL-8 was involved in the promotion of invasion of Gastric Cancer (GC), however the underlying mechanism by which IL-8 was observed to be able to promote invasion remains unknown. Here, in our study, IL-8 was shown to be significantly up-regulated in GC compared with paired normal control tissues whose expression was markedly associated with inferior overall prognosis; and IL-8 was displayed to be capable of directly interacting with metadherin (MTDH), which in turn can up-regulate IL-8 expression. Blockage of IL-8/MTDH using specific mono-antibody can abolish the invasion IL-8 mediated. Taken together, our results may provide a novel explanation of working mechanism of IL-8 in the invasion of GC.

Fabrication of MgFe2O4/MoS2 Heterostructure Nanowires for Photoelectrochemical Catalysis.

A novel one-dimensional MgFe2O4/MoS2 heterostructure has been successfully designed and fabricated. The bare MgFe2O4 was obtained as uniform nanowires through electrospinning, and MoS2 thin film appeared on the surface of MgFe2O4 after further chemical vapor deposition. The structure of the MgFe2O4/MoS2 heterostructure was systematic investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectrometry (XPS), and Raman spectra. According to electrochemical impedance spectroscopy (EIS) results, the MgFe2O4/MoS2 heterostructure showed a lower charge-transfer resistance compared with bare MgFe2O4, which indicated that the MoS2 played an important role in the enhancement of electron/hole mobility. MgFe2O4/MoS2 heterostructure can efficiently degrade tetracycline (TC), since the superoxide free-radical can be produced by sample under illumination due to the active species trapping and electron spin resonance (ESR) measurement, and the optimal photoelectrochemical degradation rate of TC can be achieved up to 92% (radiation intensity: 47 mW/cm(2), 2 h). Taking account of its unique semiconductor band gap structure, MgFe2O4/MoS2 can also be used as an photoelectrochemical anode for hydrogen production by water splitting, and the hydrogen production rate of MgFe2O4/MoS2 was 5.8 mmol/h·m(2) (radiation intensity: 47 mW/cm(2)), which is about 1.7 times that of MgFe2O4.

Halichoblelide D, a New Elaiophylin Derivative with Potent Cytotoxic Activity from Mangrove-Derived Streptomyces sp. 219807.

During our search for interesting bioactive secondary metabolites from mangrove actinomycetes, the strain Streptomyces sp. 219807 which produced a high elaiophylin yield of 4486 mg/L was obtained. A new elaiophylin derivative, halichoblelide D (1), along with seven known analogues 2-8 was isolated and identified from the culture broth. Their chemical structures were determined by detailed analysis of 1D and 2D NMR and HRMS data. The absolute configuration of halichoblelide D (1) was confirmed by comparing the CD spectrum with those of the reported analogues. Compounds 1-7 exhibited potent cytotoxic activities against HeLa and MCF-7 cells with IC50 values ranging from 0.19 to 2.12 µM.

KDM3A interacted with p53K372me1 and regulated p53 binding to PUMA in gastric cancer.

Chemoresistance remains a major problem in the treatment of gastric cancer patients, leading to the serious limitation of efficacy of chemotherapeutic regime. However, the underlying mechanism remains largely unknown. In our present study, we for the first time found that knock down of KDM3A can promote apoptosis induced by chemoreagent Cisplatin and Paclitaxel through p53. Mechanistically, through promoting p53 binding to the promoter of PUMA. However, knock down of KDM3A as such doesn't affect p53 level. In addition, KDM3A can interact with p53K372me1 in protein-protein interaction fashion, leading to the inactivation of p53, may eventually leading to chemoresistance of gastric cancer.

Ag-Decorated ATaO3 (A = K, Na) Nanocube Plasmonic Photocatalysts with Enhanced Photocatalytic Water-Splitting Properties.

Tantalate semiconductor nanocrystals have been at the forefront of the photocatalytic conversion of solar energy to supply hydrogen owing to their favorable and tunable optical and electronic properties as well as advances in their synthesis. However, a narrow band gap is required for response to improve the efficiency of the photocatalysts. Here we propose an efficient enhancement of the H2 generation under simulated sunlight and visible light irradiation by a dispersion of Ag-decorated KTaO3 and NaTaO3 nanocubes. X-ray diffraction and UV-vis diffuse reflectance spectra are used to characterize the products. Transmission electron microscope (TEM) and high-resolution high-angle annular dark-field scanning TEM (HAADF-STEM) images show that the Ag nanoparticles (NPs) are uniformly loaded on the surfaces of KTaO3 and NaTaO3. The photocatalytic water-splitting results over Ag-decorated KTaO3 and NaTaO3 show that the rate for H2 evolution from aqueous CH3OH solutions is up to 185.60 and 3.54 µmol/h·g under simulated sunlight and the rate for H2 evolution is more than 2 times than that of pure NaTaO3 and KTaO3 materials. However, under purely visible light illumination the highest H2 evolution of 25.94 and 0.83 µmol/h·g is observed in the case of Ag-decorated KTaO3 and NaTaO3 nanocubes. To the best of our knowledge, this is the first time that the photocatalytic water-splitting activity of the prepared Ag-decorated KTaO3 and NaTaO3 nanocubes has been reported.

Genotype-driven isolation of enterocin with novel bioactivities from mangrove-derived Streptomyces qinglanensis 172205.

The type II polyketide synthase (PKS) natural product enterocin (1) was isolated from a mangrove-derived novel species Streptomyces qinglanensis 172205 guided by genome sequence, and its putative biosynthetic gene cluster was revealed. Its natural analogues 5-deoxyenterocin (2) and wailupemycin A-C (3-5) were also identified by tandem mass spectrometry. By feeding experiments with aryl acids, strain 172205 was proved to incorporate partial exogenous starter units into enterocin- and wailupemycin-based analogues, thus being a new and suitable microorganism for engineering unnatural enc-derived polyketide metabolites. In addition, biological assays indicated that enterocin showed obvious inhibitory activity against ß-amyloid protein (Aß1-42) fibrillation and moderate cytotoxicity against HeLa and HepG2 for the first time.

Aberration measurement technique based on an analytical linear model of a through-focus aerial image.

We propose an in situ aberration measurement technique based on an analytical linear model of through-focus aerial images. The aberrations are retrieved from aerial images of six isolated space patterns, which have the same width but different orientations. The imaging formulas of the space patterns are investigated and simplified, and then an analytical linear relationship between the aerial image intensity distributions and the Zernike coefficients is established. The linear relationship is composed of linear fitting matrices and rotation matrices, which can be calculated numerically in advance and utilized to retrieve Zernike coefficients. Numerical simulations using the lithography simulators PROLITH and Dr.LiTHO demonstrate that the proposed method can measure wavefront aberrations up to Z(37). Experiments on a real lithography tool confirm that our method can monitor lens aberration offset with an accuracy of 0.7 nm.

Pixel-based defect detection from high-NA optical projection images.

The reconstruction of subwavelength defects from measured images of high-NA-projection systems is demonstrated. A structure consisting of a few small unknown defects in an otherwise known mask layout is studied. The footprint of the defect, which is the measured or simulated difference between images of masks with and without defects, is used to reconstruct the position, shape, and transmission of defects. The requirement is that the few unknown defects are sparsely located in the known mask layout. The technique relies on the cost function and an appropriate optimizer. The dependency of the reconstruction results on defect sizes and types of defects is presented. Moreover, the sensitivity of the technique to noise is investigated.

Natural products from mangrove actinomycetes.

Mangroves are woody plants located in tropical and subtropical intertidal coastal regions. The mangrove ecosystem is becoming a hot spot for natural product discovery and bioactivity survey. Diverse mangrove actinomycetes as promising and productive sources are worth being explored and uncovered. At the time of writing, we report 73 novel compounds and 49 known compounds isolated from mangrove actinomycetes including alkaloids, benzene derivatives, cyclopentenone derivatives, dilactones, macrolides, 2-pyranones and sesquiterpenes. Attractive structures such as salinosporamides, xiamycins and novel indolocarbazoles are highlighted. Many exciting compounds have been proven as potential new antibiotics, antitumor and antiviral agents, anti-fibrotic agents and antioxidants. Furthermore, some of their biosynthetic pathways have also been revealed. This review is an attempt to consolidate and summarize the past and the latest studies on mangrove actinomycetes natural product discovery and to draw attention to their immense potential as novel and bioactive compounds for marine drugs discovery.