Ecological Engineering and Restoration of Eroded Muddy Coasts in South East Asia: Knowledge Gaps and Recommendations

Ecological engineering (EE) was employed for developing strategies for stabilizing eroded muddy coasts (EMCs). However, there was a limited analysis of these EE strategies with respect to design, performance, and lessons learned. This study employed a critical review for addressing the limitations. There were four EE models designed with different restoration interventions for stabilizing EMCs. The models using active interventions have not been cost-effective in controlling erosion because the interventions failed to achieve their goals or were costly and unnecessary. Of the two passive intervention models, the one with structures constructed from onshore proved to be more cost-effective in terms of construction costs, the survival rate of transplanted seedlings, and levels of sea mud accumulation. Interventions with adequate consideration of the muddy coastal ecological processes and the ecological reasoning for the positioning of these interventions play a crucial role in stabilizing EMCs. A passive restoration model using gradually expanded interventions should be promoted in order to ensure sustainable management of EMCs in the future

Disinfection performance of an ultraviolet lamp: a CFD investigation

Ultraviolet (UV)-based devices have shown their effectiveness on various germicidal purposes. To serve their design optimisation, the disinfection effectiveness of a vertically cylindrical UV lamp, whose wattage ranges from P = 30 − 100 W, is numerically investigated in this work. The UV radiation is solved by the Finite Volume Method together with the Discrete Ordinates model. Various results for the UV intensity and its bactericidal effects against several popular virus types, i.e., Corona-SARS, Herpes (type 2), and HIV, are reported and analysed in detail. Results show that the UV irradiance is greatly dependent on the lamp power. Additionally, it is indicated that the higher the lamp wattage employed, the larger the bactericidal rate is observed, resulting in the greater effectiveness of the UV disinfection process. Nevertheless, the wattage of P ≤ 100W is determined to be insufficient for an effective disinfection performance in a whole room; higher values of power must hence be considered in case intensive sterilization is required. Furthermore, the germicidal effect gets reduced with the viruses less sensitive to UV rays, e.g, the bactericidal rate against the HIV virus is only ∼8.98% at the surrounding walls

THỰC VẬT PHÙ DU VÙNG BIỂN VEN BỜ ĐÀ NẴNG

Phytoplankton, especially community characteristics, in coastal waters of Da Nang have not been well studied. This present study analyzed data of phytoplankton for diversity and abundance from surveys from 2002 to 2016 at 44 stations in the coastal Da Nang waters. A total of 316 taxa from 9 classes were identified: Dinophyceae (134 taxa), Mediophyceae (77 taxa), Coscinodiscophyceae (44 taxa), Bacillariophyceae (36 taxa), Cyanophyceae (3 taxa), Dictyochophyceae (2 taxa), Bacillariophyta classis incertae sedis (1 taxon), Conjugatophyceae (1 taxon) and Thecofilosea (1 taxon). A list of 36 species of potentially harmful microalgae was recorded in coastal waters of Da Nang. In which, Pseudo-nitzschia spp. often had higher cell densities in some locations during the northeast monsoon. Analyzing diversity indices in different locations showed that there were significance differences of Margalef and Shannon indices, low in estuarine area (CS) and higher in the south of Son Tra peninsula (NST). Meanwhile no strong differences of Pielou and Simpson indices were found among the locations. However, there were strong differences of Margalef, Simpson and Pielou indices, which were found over the three studied years (2004, 2005, and 2006), mainly in NST, the northeast of Son Tra peninsula (DBST) and Da Nang bay (VDN). Analysis of species accumulation curves indicated that only 56–95% of species  was found compared to maximal expected species richness in all studied locations. DMS analysis showed that there was year-based similarity among the years (ca. 50% of similarity) of phytoplankton communities. Among the studied years, average phytoplankton cell densities in Da Nang bay and the northeast of Son Tra were higher than those in other years and locations. This present study on species richness, expected species richness and variation in phytoplankton abundance suggested that there is a need of increasing sampling efforts, especially in riverine area and DBST for better understanding of characteristics of phytoplankton communities in coastal Da Nang waters.Thực vật phù du là đối tượng ít được nghiên cứu ở vùng biển ven bờ Đà Nẵng, nhất là những đặc trưng về thành phần loài và cấu trúc quần xã. Trong bài báo này, chúng tôi phân tích số liệu về đa dạng loài và sự phong phú của thực vật phù du thu thập được trong các chuyến khảo sát từ năm 2002 đến năm 2016 ở 44 trạm trong vùng biển ven bờ Đà Nẵng. Kết quả phân tích đã xác định được 316 loài và dưới loài thuộc 9 lớp tảo khác nhau. Trong các loài thực vật phù du ghi nhận được, có 36 loài tảo có khả năng gây hại, trong đó mật độ của Pseudo-nitzschia spp. cao hơn tại một số khu vực trong thời kỳ gió mùa Đông Bắc. Phân tích các chỉ số theo từng khu vực, có thể thấy chỉ số giàu có loài Margalef và chỉ số đa dạng Shannon khác nhau đáng kể giữa các khu vực, thấp ở cửa sông trong vịnh Đà Nẵng và cao ở nam bán đảo Sơn Trà. Trong khi các chỉ số cân bằng Pielou và đa dạng Simpson lại không khác biệt giữa các khu vực. Tuy nhiên, sự đa dạng và độ giàu có loài lại có sự khác biệt giữa các năm 2004, 2005 và 2016, chủ yếu ở nam bán đảo Sơn Trà, đông bắc bán đảo Sơn Trà và vịnh Đà Nẵng. Phân tích độ giàu có loài cho thấy hầu hết các khu vực đều chỉ ghi nhận được từ 56% đến 95% số loài mong đợi. Phân tích cấu trúc quần xã thực vật phù du thu thể hiện sự biến động giữa các năm nghiên cứu với mức độ tương đồng trong năm xấp xỉ 50%. So sánh trung bình mật độ thực vật phù du thu của từng khu vực cho thấy mật độ vào năm 2005 cao hơn hẳn so với các năm khác ở vịnh Đà Nẵng và đông bắc Sơn Trà. Các phân tích về độ giàu có loài, loài mong đợi và biến động mật độ thực vật phù du thu cho thấy dù vùng biển nghiên cứu được ghi nhận thành phần loài thực vật phù du thu cao, nhưng số lượng trạm và thời gian thu mẫu ở vùng biển Đà nẵng nhất là khu vực cửa sông cần được thu thập nhiều hơn, vẫn cần thu thập thêm vật mẫu ở tất cả các khu vực, nhất là vùng cửa sông trong vịnh Đà Nẵng và đông bắc bán đảo Sơn Trà

In-Channel-Grown Polypyrrole Nanowire for the Detection of DNA Hybridization in an Electrochemical Microfluidic Biosensor

A triple electrode setup with a Pt pseudo-reference electrode integrated in a polydimethylsiloxane- (PDMS-) based microchamber was designed and fabricated. The integrated electrodes were deposited onto SiO2/Si substrate by sputtering. The PDMS microchamber was patterned using an SU-8 mold and sealed with electrodes in oxygen plasma. Polypyrrole nanowires (PPy NWs) were electrochemically grown in situ at an accurate position of the working electrode in the sealed microchamber instead of in an open system. The DNA probe sequences were simply introduced into the channel to form bonds with the nanowires. A detection limit of 20 pM was achieved using a lock-in amplifier. The electrochemical characteristics produced by the hybridization of DNA strands in the microchamber showed a good signal/noise ratio and high sensitivity. Measurement of the DNA sensor in narrow space also required much less volume of the analytical sample compared with that in an open measuring cell. Results showed that this simple system can potentially fabricate nanostructures and detect bio/chemical molecules in a sealed system

Chemical Components of Essential Oils From the Leaves of Seven Species Belonging to Rutaceae Family from Binh Chau-Phuoc Buu Nature Reserve, Vietnam

Several plant species of the Rutaceae family are medicinal plants, oil bearing and food crops. To provide more information for utilization of some species of this family in Binh Chau-Phuoc Buu Nature Reserve, we extracted essential oils from the leaves of seven species of the Rutaceae family: Acronychia pedunculata (L.) Miq., Atalantia citroides Pierre ex Guillaumin, Clausena excavata Burm.f., Glycosmis pentaphylla (Retz.) DC., Luvunga scandens (Roxb.) Buch.-Ham. ex Wight & Arn, Melicope pteleifolia (Champ. ex Benth.) T.G. Hartley, and Micromelum sp., via hydrodistillation, and identified their components using GC/MS analysis. A total of 60 compounds were identified from essential oils of seven species. The main components of the essential oils isolated from five species, including A. pedunculata, C. excavata, M. pteleifolia, G. pentaphylla, and Micromelum sp., were caryophyllene (57.63% and 55.41% in A. pedunculata and C. excavata, respectively), 1,9-decadiyne (32.59%, M. pteleifolia), β-ocimene (23.10%, G. pentaphylla), and 3-carene (58.03%, Micromelum sp.). Additionally, this study revealed the chemical composition of essential oils of L. scandens and A. citroides for the first time. The main constituent of A. citroides was 7-oxabicyclo[4.1.0] heptane, 3-oxiranyl- (53.91%) and that of L. scandens was caryophyllene (34.66%). These findings provide the basis for further application of these species in medicine

Microwave-Assisted Synthesis of Chitosan/Polyvinyl Alcohol Silver Nanoparticles Gel for Wound Dressing Applications

The purpose of this study was to fabricate chitosan/poly(vinyl alcohol)/Ag nanoparticles (CPA) gels with microwave-assistance for skin applications. Microwave irradiation was employed to reduce silver ions to silver nanoparticles and to crosslink chitosan (CS) with polyvinyl alcohol (PVA). The presence of silver nanoparticles in CPA gels matrix was examined using UV-Vis spectroscopy, transmission electron microscopy, and X-ray diffraction. The interaction of CS and PVA was analysed by Fourier transform infrared spectroscopy. The release of silver ions was determined by atomic absorption spectrometry. The antimicrobial properties of CPA gels against P. aeruginosa and S. aureus were investigated using agar diffusion method. Finally, the biocompatibility and wound-healing ability of the gels were studied using fibroblast cells (in vitro) and mice models (in vivo). In conclusion, the results showed that CPA gels were successfully fabricated using microwave irradiation method. These gels can be applied to heal an open wound thanks to their antibacterial activity and biocompatibility

Palliative Radiation Therapy for Vertebral Metastases and Metastatic Cord Compression in Patients Treated With Anti-PD-1 Therapy

Background: There is increasing use of immune checkpoint blockade (ICB) across multiple cancer types, including in patients at risk for vertebral metastases and cord compression. These patients are often treated with palliative radiotherapy (PRT); however, data evaluating the combination of PRT and ICB in patients with vertebral metastases is limited. Furthermore, patients with cord compression are generally excluded from prospective clinical trials. Therefore, we retrospectively evaluated outcomes following PRT and PD-1 inhibition in patients with vertebral metastases.Methods: We performed a retrospective chart review of 37 consecutive patients (total 57 lesions) treated with radiation for vertebral metastases who also received PD-1 inhibition. Patient, treatment and outcomes data were abstracted from the medical records.Results: Histologies included non-small cell lung cancer (n = 21), renal cell carcinoma (n = 9) and melanoma (n = 7). Out of 57 lesions,18 involved >1 segments of the vertebral column. There were isolated lesions in thoracic (16), lumbar (9), cervical (6), and sacral (8) vertebrae. Presenting symptoms included pain (19), numbness (10), and weakness (3). Eleven patients were asymptomatic. Radiologic cord compression was present in 12, epidural extension in 28 and compression fracture in 14. Eleven patients underwent surgical decompression prior to the onset of RT. Median radiation dose was 24 Gy (range 8–30 Gy). Stereotactic radiation was delivered in 4 patients; 33 patients received conformal RT. 21 patients received PD-1 inhibition after RT, 9 before RT and 7 with RT. Seven patients received concurrent CTLA-4 inhibitors with anti-PD-1 therapy.Treatment was in general well-tolerated. Toxicities included fatigue (6), transient pain flare (1), nausea/vomiting (1) and G1 skin changes (1). All patients reported some degree of pain relief. Numbness/weakness was improved in 6 of 13 patients with baseline symptoms (46%) and this was more likely in patients that received vertebral radiation after starting PD-1 inhibitors (71 vs. 17%, p = 0.04). Most patients (22 of 33 evaluable patients, 67%) had stability of irradiated lesions on subsequent follow up imaging performed at median of 30 days from RT, whereas 3 had a complete local response and 4 had a partial local response.Conclusions: We demonstrate that PRT administered to vertebral metastases was well-tolerated and effective in patients treated with PD-1 inhibitors. There was an encouraging rate of pain reduction and neurological improvement

Risk factors for cannula-associated arterial thrombosis following extracorporeal membrane oxygenation support: a retrospective study

Background Hemostatic dysfunction during extracorporeal membrane oxygenation (ECMO) due to blood-circuit interaction and the consequences of shear stress imposed by flow rates lead to rapid coagulation cascade and thrombus formation in the ECMO system and blood vessels. We aimed to identify the incidence and risk factors for cannula-associated arterial thrombosis (CaAT) post-decannulation. Methods A retrospective study of patients undergoing arterial cannula removal following ECMO was performed. We evaluated the incidence of CaAT and compared the characteristics, ECMO machine parameters, cannula sizes, number of blood products transfused during ECMO, and daily hemostasis parameters in patients with and without CaAT. Multivariate analysis identified the risk factors for CaAT. Results Forty-seven patients requiring venoarterial ECMO (VA-ECMO) or hybrid methods were recruited for thrombosis screening. The median Sequential Organ Failure Assessment score was 11 (interquartile range, 8–13). CaAT occurred in 29 patients (61.7%), with thrombosis in the superficial femoral artery accounting for 51.7% of cases. The rate of limb ischemia complications in the CaAT group was 17.2%. Multivariate analysis determined that the ECMO flow rate–body surface area (BSA) ratio (100 ml/min/m2) was an independent factor for CaAT, with an odds ratio of 0.79 (95% confidence interval, 0.66–0.95; P=0.014). Conclusions We found that the incidence of CaAT was 61.7% following successful decannulation from VA-ECMO or hybrid modes, and the ECMO flow rate–BSA ratio was an independent risk factor for CaAT. We suggest screening for arterial thrombosis following VA-ECMO, and further research is needed to determine the risks and benefits of such screening

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions

Pichia pastoris versus Saccharomyces cerevisiae:a case study on the recombinant production of human granulocyte-macrophage colony-stimulating factor

BACKGROUND: Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) is a glycoprotein that has been approved by the FDA for the treatment of neutropenia and leukemia in combination with chemotherapies. Recombinant hGM-CSF is produced industrially using the baker's yeast, Saccharomyces cerevisiae, by large-scale fermentation. The methylotrophic yeast, Pichia pastoris, has emerged as an alternative host cell system due to its shorter and less immunogenic glycosylation pattern together with higher cell density growth and higher secreted protein yield than S. cerevisiae. In this study, we compared the pipeline from gene to recombinant protein in these two yeasts. RESULTS: Codon optimization in silico for both yeast species showed no difference in frequent codon usage. However, rhGM-CSF expressed from S. cerevisiae BY4742 showed a significant discrepancy in molecular weight from those of P. pastoris X33. Analysis showed purified rhGM-CSF species with molecular weights ranging from 30 to more than 60 kDa. Fed-batch fermentation over 72 h showed that rhGM-CSF was more highly secreted from P. pastoris than S. cerevisiae (285 and 64 mg total secreted protein/L, respectively). Ion exchange chromatography gave higher purity and recovery than hydrophobic interaction chromatography. Purified rhGM-CSF from P. pastoris was 327 times more potent than rhGM-CSF from S. cerevisiae in terms of proliferative stimulating capacity on the hGM-CSF-dependent cell line, TF-1. CONCLUSION: Our data support a view that the methylotrophic yeast P. pastoris is an effective recombinant host for heterologous rhGM-CSF production