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1.
Environ Sci Pollut Res Int ; 31(18): 26773-26789, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38456975

ABSTRACT

In this study, CoCr layered double hydroxide material (CoCr-LDH) was prepared and used as an effective catalyst for peroxymonosulfate (PMS) activation to degrade organics in water. The prepared CoCr-LDH material had a crystalline structure and relatively porous structure, as determined by various surface analyses. In Rhodamine B (RhB) removal, the most outstanding PMS activation ability belongs to the material with a Co:Cr molar ratio of 2:1. The removal of RhB follows pseudo-first-order kinetics (R2 > 0.99) with an activation energy of 38.23 kJ/mol and efficiency of 98% after 7 min of treatment, and the total organic carbon of the solution reduced 47.2% after 10 min. The activation and oxidation mechanisms were proposed and the RhB degradation pathways were suggested with the key contribution of O2•- and 1O2. Notably, CoCr-LDH can activate PMS over a wide pH range of 4 - 9, and apply to a wide range of organic pollutants and aqueous environments. The material has high stability and good recovery, which can be reused for 5 cycles with a stable efficiency of above 88%, suggesting a high potential for practical recalcitrant water treatment via PMS activation by heterogeneous catalysts.


Subject(s)
Peroxides , Water Pollutants, Chemical , Water Purification , Water Pollutants, Chemical/chemistry , Peroxides/chemistry , Water Purification/methods , Rhodamines/chemistry , Kinetics , Oxidation-Reduction , Catalysis
2.
Ecol Evol ; 14(2): e11033, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38362163

ABSTRACT

The Squaretail mullet, Ellochelon vaigiensis, is a commercial fish species distributed throughout the Indo-Pacific region. This species tolerates wide variations in salinity, having been reported from both freshwater and marine habitats. Although economically significant, there is little information on its reproduction, especially in the Vietnamese Mekong Delta (VMD), where it is heavily extracted. Our study elucidates the breeding pattern, seasonality, first length at maturity, as well as potential and relative fecundity of this species. Fish specimens were collected by trawl nets from November 2020 to October 2021 at four estuarine sites within the VMD. We found this species to be a synchronous spawner, with peaks in reproductive activity from June to September. In the populations we surveyed, there was significant dominance of males (1.26:1.00) based on 942 fish samples (526 males and 416 females). The length at 50% maturity for females was significantly higher than for males at all sites and ranged from 10.6 to 19.3 cm. The diameter of the eggs examined for this species exhibited slight variation, from 0.43 to 0.54 mm. The potential fecundity ranged from 246,254 ± 35,878 to 411,970 ± 54,370 eggs, corresponding to female length and weight of 26.7-32.6 cm and 102.97-234.19 g, respectively. Relative fecundity values were highest at Thanh Phu, Ben Tre (6388 ± 605 eggs), and Dong Hai, Bac Lieu (6461 ± 637 eggs), followed by Tran De, Soc Trang (4729 ± 408), and were found to be lowest at Duyen Hai, Tra Vinh (3117 ± 223 eggs). Information on reproductive behavior in this species has far-reaching impacts on sustainable extractions, stock conservation, and aquaculture.

3.
RSC Adv ; 13(51): 36060-36070, 2023 Dec 08.
Article in English | MEDLINE | ID: mdl-38090075

ABSTRACT

In this study, we fabricated a composite of NiO-ZnO/PANI-CNTs on a fluorine tin oxide (FTO) electrode and examined the electrochemical sensing behavior of the modified electrode to detect methanol in aqueous solution. The structural, morphological, and electrochemical properties of the composite were characterized using various methods such as X-ray diffraction (XRD), EDS, FTIR, X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and electrochemical techniques such as cyclic voltammetry (CV) and chronoamperometry (CA). The composite-based electrode showed excellent electrocatalytic activity and selectivity for methanol oxidation. The calibration equation obtained was ΔI = 0.0003 × CMeOH + 0.02811, with a high correlation coefficient of 0.9993, over a wide detection range of 0 to 500 mM. The material exhibits great potential for the fabrication of sensors to detect methanol in commercial products. Real gasoline samples have been selected to evaluate the practical performance and feasibility of this as-prepared sensor. The experimental data indicated that the recovery of gasoline samples is about 98%, indicating this to be an appropriate detection procedure for effective electrochemical determination of MeOH in real gasoline samples.

4.
RSC Adv ; 13(50): 35339-35348, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-38058561

ABSTRACT

This study delves into the advanced integration of a ternary heterogeneous Z-scheme photocatalyst, TiO2/CuInS2/OCN (OCN: O-g-C3N4), with carbon quantum dot (CQD) to improve the degradation efficiency of reactive yellow 145 (RY145) dye in water. Through a systematic examination, we elucidated the photocatalytic mechanisms and the role of radicals, electrons, and holes in the treatment process. Our findings revealed that this novel catalyst integration significantly boosted RY145 degradation efficiency, achieving 98.2%, which is markedly higher than the efficiencies which could be achieved using TiO2/CuInS2/OCN alone. Moreover, the TiO2/CuInS2/OCN/CQD photocatalyst demonstrated superior rate performance over its components. Comprehensive evaluations, including photoelectrochemical and radical tests, further confirmed the efficiency of the integrated system, adhering to Z-scheme principles. The catalyst showcased remarkable stability, with over 94% reusability after five reaction cycles. These findings pave the way for the potential use of the TiO2/CuInS2/OCN/CQD photocatalyst as an innovative solution for water pollutant treatment via photocatalytic technology.

5.
Heliyon ; 9(9): e20139, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37809956

ABSTRACT

Butis genus is characterised by their small body size and morphological variability, allowing them to adapt to different habitats. This paper analyses the mitochondrial cytochrome C oxidase subunit I gene sequences and morphology of Butis for identification purposes and to understand genetic relationships. The morphological characteristics of Butis koilomatodon differed obviously from Butis humeralis and Butis butis. After classification based on morphology, the total deoxyribonucleic acid of fish samples was isolated, and the mitochondrial cytochrome C oxidase subunit I genes were successfully amplified using the polymerase chain reaction method. At approximately 617bp, the obtained mitochondrial cytochrome C oxidase subunit I gene sequences were highly similar to the reference sequences on Genbank (85.90-100%). The phylogenetic graphic was divided into five distinct groups, where B. koilomatodon was grouped in one group; and B. humeralis and B. butis were grouped together. The results suggest that B. humeralis was an entirely different species from B. butis, with a mean genetic divergence of up to 14%. However, further studies using a combination of other types of deoxyribonucleic acid barcoding together with morphological features should be undertaken to confirm these findings.

6.
RSC Adv ; 13(30): 20994-21007, 2023 Jul 07.
Article in English | MEDLINE | ID: mdl-37448638

ABSTRACT

In the present study, the biosynthesis of stable silver nanoparticles (BioAgNPs) was accomplished successfully for the first time by using an aqueous extract derived from the buds of Syzygium nervosum (SN) as both a reducing and a stabilizing agent. Transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM) investigations revealed that the biosynthesized BioAgNPs were predominantly spherical with an average size of 10-30 nm. It was found that the outstanding stability of the BioAgNPs colloidal solution was assigned to the additive effect of the surrounding protective organic layer and the highly negatively charged surface of the nanoparticles. Consequently, good antibacterial activity was demonstrated by the colloidal BioAgNPs solution against four distinct bacterial strains, including Gram-positive S. aureus and B. subtilis as well as Gram-negative E. coli and S. typhi. Interestingly, the biosynthesized BioAgNPs displayed greater antibacterial activity even when tested at low doses against Gram-negative S. typhi. In addition, the biogenic AgNPs demonstrated a significant level of catalytic activity in the process of converting 2-NP, 3-NP, and 4-NP into aminophenols within 15 min, with reaction rate constants of 9.0 × 10-4, 10 × 10-4, and 9.0 × 10-4 s-1, respectively. BioAgNPs formulations were assessed against anthracnose disease in tea plants and were found to be as effective as the positive control at a dose of 20-fold dilution, but less effective at a dose of 30-fold dilution. Both doses of BioAgNPs formulations significantly suppressed Colletotrichum camelliae (anthracnose disease) without affecting the growth of the tea plants.

7.
Heliyon ; 9(6): e16943, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37389047

ABSTRACT

Condensation of quinaldine with 4,6-di (tert-butyl)-3-nitro-1,2-benzoquinone results in the formation of 5,7-di (tert-butyl)-2-(quinoline-2-yl)-1,3-tropolone, 5,7-di (tert-butyl)-4-nitro-2-(quinoline-2-yl)-1,3-tropolone, 3,3-dimethyl-2-(5-hydroxy-4-nitro-3-tert-butyl-6-quinoline-2-yl-pyridine-2-yl)butanoic acid, 6-(2,2-dimethylprop-3-yl)-5-tert-butyl-4-nitro-2-(quinoline-2-yl)-pyridine-3-ol, 1,7-di (tert-butyl)-3-(quinoline-2-yl)-2-azabicyclo-[3.3.0]octa-2,7-diene-4,6-dione-N-oxide. The formation of 1,3-tropolone and pyridine-2-yl butanoic acid derivatives proceeds through a ring expansion and 2-azabicyclo [3.3.0]octa-2,7-diene-4,6-dione-N-oxide via the contraction of the o-quinone ring. The structure of the heterocyclic compounds obtained was justified by X-ray diffraction analysis, NMR spectroscopy, IR- and HRMS-spectrometry, and the proposed mechanisms of their formation include the participation of an intermediate product of the expansion reaction of the o-quinone cycle - 5,7-di (tert-butyl)-4-nitro-2-(quinoline-2-yl)-cyclohepta-1,3,5-triene-1,3-diol, which was first isolated preparatively. The DFT/B3LYP/6-311++G** methods were used to determine the thermodynamic stability of tautomeric forms of intermediate products, as well as the relative stability of NH and OH tautomers of 5,7-di (tert-butyl)-2-(quinolin-2-yl)-1,3-tropolone and 5,7-di (tert-butyl)-4-nitro-2-(quinolin-2-yl)-1,3-tropolone.

8.
RSC Adv ; 13(28): 19317-19324, 2023 Jun 22.
Article in English | MEDLINE | ID: mdl-37377878

ABSTRACT

Hexagonal NaYF4:Tm, Yb upconversion (UC) phosphors with excellent UC luminescence quantum efficiency and chemical stability meet demands for applications in bioimaging and anti-counterfeiting printing. In this work, a series of NaYF4:Tm, Yb upconversion microparticles (UCMPs) with different concentrations of Yb were synthesized by a hydrothermal method. Then, the UCMPs become hydrophilic through surface oxidation of the oleic acid (C-18) ligand to azelaic acid (C-9) using the Lemieux-von Rodloff reagent. The structure and morphology of UCMPs were investigated by X-ray diffraction and scanning electron microscopy. The optical properties were studied using diffusion reflectance spectroscopy and photoluminescent spectroscopy under 980 nm laser irradiation. The emission peaks of the Tm3+ ions are 450, 474, 650, 690, and 800 nm, attributed to the transitions from the excited state to ground state 3H6. These emissions are the results of two or three photon absorption through multi-step resonance energy transfer from excited Yb3+, confirmed via a power-dependent luminescence study. The results show that the crystal phases and luminescence properties of the NaYF4:Tm, Yb UCMPs are controlled by changing the Yb doping concentration. The printed patterns are readable under the excitation of a 980 nm LED. Moreover, the zeta potential analysis shows that the UCMPs after surface oxidation are water dispersible. In particular, the naked eye can observe the enormous upconversion emissions in UCMPs. These findings indicated that this fluorescent material is an ideal candidate for anti-counterfeiting and biological applications.

9.
Heliyon ; 9(5): e16106, 2023 May.
Article in English | MEDLINE | ID: mdl-37215891

ABSTRACT

The Glossogobius species play an essential role in food supply and are distributed widely from the marine to freshwater, especially in the Mekong Delta, Vietnam (VMD). Some of their morphometrics and meristics are observed to vary with species and sampling sites. Therefore, the present study aims to verify if their mitochondrial Cytochrome b (Cytb) gene, one of the popular gene sequences used in fish phylogenic variation assessment, varies with species and sampling sites in the VMD. The Cytb gene size was 1300 bp for GcytbH/GcytbL primer pair and 1045 bp for GluMuq1-F/Mixcyto937-2R. The genetic distances within and among these three fish species groups were 0-11%. The Cytb gene sequences' similarity between this study and the NCBI database was 85.84-100%. The Glossogobius specimens were observed to disperse in small branches of the phylogenetic tree with a low K2P value, suggesting that the Cytb genetic diversity may be low among species.

10.
Chemosphere ; 329: 138607, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37037353

ABSTRACT

Photocatalysts based on titanium dioxide (TiO2) were widely applied to solve environmental problems such as water and air pollution treatment. Currently, the application of these compounds for food packaging is increasing. This study prepared silver (Ag) doped TiO2 photocatalyst (Ag/TiO2) for the decomposition of gas ethylene (Eth), which is the main factor that causes fruits to over-ripen and damage or decay. It found that the doping of Ag could improve the optical property and light adsorption ability of Ag/TiO2 photocatalyst, which directly enhanced the photocatalytic decomposition of Eth performance. Under visible light, Ag/TiO2 could depredate 91.2% of Eth, while the removal performance by using the original TiO2 was 43.9%. The increased initial concentration of Eth from 5 to 30 ppm could inhibit the photocatalytic efficiency of Ag/TiO2 from 98.6 to 69.2%. Besides, the relative humidity and gas flow rate are roles in the Eth decomposition process. The recycling experiment confirmed that Ag/TiO2 had good reusability with a slight loss in photocatalytic performance (18.6%) after ten cycles tested. The future protective application of Ag/TiO2 for food protection during storage and transportation is discussed. This work provides a potential method to remove gas ethylene, reduce the ripening process and extend the shelf life of fruits.


Subject(s)
Light , Titanium , Titanium/pharmacology , Silver/pharmacology , Ethylenes , Catalysis
11.
Nanomaterials (Basel) ; 13(5)2023 Mar 05.
Article in English | MEDLINE | ID: mdl-36903818

ABSTRACT

Oxyfluoride glass-ceramics (OxGCs) with the molar composition 80SiO2-20(1.5Eu3+: NaGdF4) were prepared with sol-gel following the "pre-crystallised nanoparticles route" with promising optical results. The preparation of 1.5 mol % Eu3+-doped NaGdF4 nanoparticles, named 1.5Eu3+: NaGdF4, was optimised and characterised using XRD, FTIR and HRTEM. The structural characterisation of 80SiO2-20(1.5Eu3+: NaGdF4) OxGCs prepared from these nanoparticles' suspension was performed by XRD and FTIR revealing the presence of hexagonal and orthorhombic NaGdF4 crystalline phases. The optical properties of both nanoparticles' phases and the related OxGCs were studied by measuring the emission and excitation spectra together with the lifetimes of the 5D0 state. The emission spectra obtained by exciting the Eu3+-O2- charge transfer band showed similar features in both cases corresponding the higher emission intensity to the 5D0→7F2 transition that indicates a non-centrosymmetric site for Eu3+ ions. Moreover, time-resolved fluorescence line-narrowed emission spectra were performed at a low temperature in OxGCs to obtain information about the site symmetry of Eu3+ in this matrix. The results show that this processing method is promising for preparing transparent OxGCs coatings for photonic applications.

12.
Chem Commun (Camb) ; 59(30): 4503-4506, 2023 Apr 11.
Article in English | MEDLINE | ID: mdl-36974924

ABSTRACT

A heavy-atom-free photosensitizer (CI) based on an imidazole-carbazole conjugate exhibited strong fluorescence emission and ROS generation via both type I and II mechanisms. In particular, CI showed efficient photodynamic therapy and fluorescence bioimaging under two-photon (TP) excitation (740 nm) toward HeLa cells with negligible dark toxicity.


Subject(s)
Photochemotherapy , Humans , Fluorescence , HeLa Cells , Photochemotherapy/methods , Carbazoles , Imidazoles
13.
Radiol Case Rep ; 18(3): 766-770, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36589495

ABSTRACT

Head and neck arteriovenous malformations are rare, congenital, and high-flow vascular malformations characterized by abnormal communication between feeding arteries and draining veins without intervening capillaries. Arteriovenous malformations are considered the most dangerous type of vascular malformation because progressive symptoms and infiltration can result in potentially life-threatening consequences. Left untreated, arteriovenous malformations can cause significant cosmetic deformities, severe bleeding, and high-output cardiac failure associated with arteriovenous shunting. The effective treatment of arteriovenous malformations located in the head and neck region is quite challenging due to high rates of recurrence and potentially lethal complications. We describe a case presenting with large arteriovenous malformations in the face and neck. Despite attempting several treatments, including external carotid artery ligation and embolization with liquid embolic agents, the patient continued to experience recurrence and symptoms of bleeding and pain. After admission, reconstructive plastic surgery was performed, supplemented by percutaneous direct puncture embolization, using glue injected into the venous and transarterial embolization. The patient was discharged with clinical recovery. Digital subtraction angiography remains the gold standard for assessing symptomatic and aggressive arteriovenous malformations, both before and after treatment. The treatment of head and neck arteriovenous malformations often requires a multidisciplinary approach to achieve the best clinical results.

14.
Ecol Evol ; 12(9): e9352, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36188496

ABSTRACT

Ellochelon vaigiensis (squaretail mullet) adapts to a wide salt spectrum, grows quickly and is easy to raise with other species, so it is the object of attention in aquaculture. Information on the biology and ecology of the species, diet, in particular, is still scattered. Here, we explore the feeding habit, feeding intensity, and food composition of the squaretail mullet. A total of 942 fish (526 males and 416 females) were collected from November 2020 to October 2021 at four coastal sites in the Mekong Delta, Vietnam. The squaretail mullet is an algi-omnivorous fish, as their relative gut length (1.81) falls into the range 1-3, and the diet is mostly based on algae. The feeding intensity is high due to the high value of the fullness index (4.39 ± 0.08%). The fullness index did not vary by sampling site and month, while RGL and FI changed depending on sex. Bacillariophyta (49.13%), detritus derived from organic matter (30.37%), and Cyanophyta (18.39%) are the dominant food items in the diet composition of E. vaigiensis, in which detritus is the most important food with the highest IRI index. Besides, Euglenophyta (1.00%), Chlorophyta (0.95%), Paramecium (0.06%), Copepoda (0.04%), Rotatoria (0.03%), Polychaeta (0.02%), and Cladocera (0.01%) are also recorded and ranked based on their biovolume. Some differences in diet composition are observed between immature and mature at different seasons and their interactions. Our results increase the knowledge about the feeding ecology of squaretail mullet and can help the sustainable management of this commercially important fish species.

15.
Int J Surg Case Rep ; 99: 107600, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36116306

ABSTRACT

BACKGROUND: Currently, intramedullary nailing for tibial fractures has very good postoperative treatment results. Combining the advantages of traditional medicine and modern medicine is a comprehensive treatment method that brings the best benefits to the patient. METHODS: The study method was a controlled clinical trial. The study included 60 patients with a definitive diagnosis of tibial fracture who underwent intramedullary nailing surgery. These patients were divided into 2 groups: with and without electroacupuncture treatment. RESULTS: Electro-acupuncture had a significant analgesic effect in 24-48 h after surgery: After 24 h or electro-acupuncture, the pain difference in the study group and the control groups was 3.03 ± 1.25 and 2.46 ± 1.33, respectively (p < 0.05). The VAS score difference between day 1 and day 2 in the study group and the control group was 0.61 ± 0.71 and 0.59 ± 0.67, respectively (p < 0.05). At 48 h postoperatively, the circumference of the calf on the fractured side in the study group and the control group was 36.1 ± 2.1 and 37.3 ± 2.2 cm, respectively (p < 0.05). At 72 h postoperatively, the circumference of the calf in the study group and the control group was 35.9 ± 2.6 and 37.6 ± 2.8 cm, respectively (p < 0.05). The effect of electro-acupuncture on bone healing did not differ between the study group and the control group (p > 0.05). During 7 days of using the treatment regimen, there were 3.3 % of patients with dizziness, 3.3 % of patients with vomiting/nausea, 3.3 % of patients with bleeding at the injection site. There was no difference in blood pressure, pulse rate, hematological indexes and biochemical indexes of patients before and after using the treatment regimen. CONCLUSION: Electro-acupuncture has a significant analgesic effect 24 h-48 h after surgery. The effect of electroacupuncture on bone healing was not different between the two groups. Electroacupuncture is a safe, effective method with few side effects.

16.
Physiother Theory Pract ; : 1-10, 2022 Aug 27.
Article in English | MEDLINE | ID: mdl-36036381

ABSTRACT

BACKGROUND AND PURPOSE: Patients with mild-to-moderate hip OA can present with pain, a decline in function, altered gait mechanics, and pain with ambulation. Body weight supported treadmill training (BWSTT) has been utilized for patients with total hip arthroplasty, hip fracture, and lumbar spinal stenosis. The purpose of this case series was to report the outcomes of patients with hip OA that received guideline adherent physical therapy care with the addition of BWSTT. Our aim was to assess changes in pain, disability, and physical performance. CASE DESCRIPTIONS: Seven patients participated in eight 1-h treatment sessions consisting of: manual therapy, therapeutic exercise, and BWSTT. Pre- and post-treatment outcome measures included: average pain rating via the Numeric Pain Rating Scale (NPRS), Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), and the Global Rate of Change (GROC). Physical performance measures included: 6-minute walk test (6MWT), stair climbing test, and 5 time sit-stand. OUTCOMES: The mean improvement in NPRS score for all subjects was 2.9 points. Mean improvement on the WOMAC was 18.5 + 24.8 pts, and the mean GROC score was +5.0 indicating a rating of "quite a bit better." The mean increase in 6MWT distance was 60.5 + 80.1 meters (median 39 m, range -3 to 230). CONCLUSIONS: Though patients participating in a multimodal rehabilitation approach including manual therapy, exercise, and BWSTT demonstrated clinically important improvements in pain and function, these changes may not correspond with gait endurance improvements in the short term.

17.
PeerJ Comput Sci ; 8: e950, 2022.
Article in English | MEDLINE | ID: mdl-35494837

ABSTRACT

Undeniably, Internet of Things (IoT) devices are gradually getting better over time; and IoT-based systems play a significant role in our lives. The pervasiveness of the new essential service models is expanding, and includes self-driving cars, smart homes, smart cities, as well as promoting the development of some traditional fields such as agriculture, healthcare, and transportation; the development of IoT devices has not shown any sign of cooling down. On the one hand, several studies are coming up with many scenarios for IoT platforms, but some critical issues related to performance, speed, power consumption, availability, security, and scalability are not yet fully resolved. On the other hand, IoT devices are manufactured and developed by different organizations and individuals; hence, there is no unified standard (uniformity of IoT devices), i.e., sending and receiving messages among them and between them and the upper layer (e.g., edge devices). To address these issues, this paper proposes an IoT Platform called BMDD (Broker-less and Microservice architecture, Decentralized identity, and Dynamic transmission messages) that has a combination of two architectural models, including broker-less and microservices, with cutting-edge technologies such as decentralized identity and dynamic message transmission. The main contributions of this article are five-fold, including: (i) proposing broker-less and microservice for the IoT platform which can reduce single failure point of brokering architecture, easy to scale out and improve failover; (ii) providing a decentralized authentication mechanism which is suitable for IoT devices attribute (i.e., mobility, distributed); (iii) applying the Role-Based Access Control (RBAC) model for the authorization process; (iv) exploiting the gRPC protocol combined with the Kafka message queue enhances transmission rates, transmission reliability, and reduces power consumption in comparison with MQTT protocol; and (v) developing a dynamic message transmission mechanism that helps users communicate with any device, regardless of the manufacturer, since it provides very high homogeneity.

18.
PeerJ ; 10: e13289, 2022.
Article in English | MEDLINE | ID: mdl-35469199

ABSTRACT

Periophthalmus chrysospilos is an amphibious fish living in mudflats from eastern India to Indonesia, including the Vietnamese Mekong Delta. Population biological traits play an important role in fishery assessment, but understanding is limited for this species. In total 1,031 specimens were caught in two regions covering four provinces, including the TVST (Duyen Hai, Tra Vinh and Tran De, Soc Trang) and BLCM (Dong Hai, Bac Lieu and Dam Doi, Ca Mau). Results found that the sex ratio was close to 1:1. The parameters of the von Bertalanffy in TVST were L∞ = 12.8 cm, K = 0.41 yr-1, t0 = -0.10 yr and in BLCM were 12.7 cm, 0.38 yr-1 and -0.08 yr, respectively. Although the growth coefficient (Φ') in BLCM (1.79), was lower than that in TVST (1.83), the species shared a similar size at first capture (7.9 cm in TVST and 7.9 cm in BLCM). The species suffered from heavy pressure of fishing in TVST as fishing mortality in TVST (2.32 yr-1) was higher than that in BLCM (1.38 yr-1), leading to the higher total mortality (Z = 3.60 yr-1) in TVST compared to BLCM (Z = 2.59 yr-1). By contrast, the species showed similar natural mortality over both sites (1.20 yr-1 in TVST and 1.22 yr-1 in BLCM). The Periophthalmus chrysospilos population was reasonably exploited because E values (0.64 in TVST and 0.53 in BLCM) were lower than E10 (0.706 in BTTV and 0.705 in STBL). Nonetheless, to avoid the consequences of overfishing, some sustainable fisheries practices should be implemented, such as protecting mangrove forests, restricting fishing during the recruitment period, using appropriate fishing tools and increasing mesh size.


Subject(s)
Conservation of Natural Resources , Perciformes , Animals , Humans , Population Dynamics , Southeast Asian People , Fisheries
19.
Ecol Evol ; 12(1): e8507, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35127029

ABSTRACT

Populations of Periophthalmus chrysospilos, the Gold-spotted mudskipper, within the Mekong Delta are facing extirpation risks due to indiscriminate harvesting for the growing aquarium and food-fish trade. This study provides some of the first information on reproductive ecology-such as spawning type and season, length at first maturity, and batch fecundity-of this species, to be used in their management. The sex ratio of wild populations, based on 1031 individuals (523 males and 508 females) is 1:1. The gonadosomatic index (GSI) values are exhibit a non-normal distribution and changed with gender, season, and site. A combination of GSIs and the monthly appearance of mature gonads suggest that this species reproduces throughout the year, with peak from July to October. This species exhibits sexual and spatial variation in size at first maturity (Lm ) as Lm is 6.2-8.6 cm in males and 6.4-7.3 cm in females. The batch fecundity (F = 2614 to 23,465 eggs/female) exhibits non-normal distribution and varies with site, with the highest values at Dam Doi, Ca Mau (13,336 ± 1,279 SE) and the lowest at Tran De, Soc Trang (6654 ± 851 SE). In addition, batch fecundity is directly proportional to body size due to high determination relationships between batch fecundity and fish size (r 2 > 0.64 for all cases). Information derived on the reproductive biology of this species can inform its conservation, sustainable exploitation, and ex situ propagation.

20.
Res Vet Sci ; 144: 98-107, 2022 May.
Article in English | MEDLINE | ID: mdl-35093722

ABSTRACT

Previously we observed that bacterial lipopolysaccharide (LPS) was able to instantly convert recombinant murine prion protein (moPrP) from an alpha-helical to a beta-sheet enriched state. The objectives of this study were to evaluate the effects of a single in vitro administration of recombinant moPrP alone or combined with detoxified lipopolysaccharide (D-LPS) on innate immunity and antibacterial gene expression in the colon of male FVB/N mice, under an Ussing chamber system. Results showed that moPrP alone affected the expression of genes related to both toll-like receptor (TLR)- and nod-like receptor (NLR)-signaling as well as pro- and anti-inflammatory responses. moPrP induced a strong antibacterial response with Slpi mRNA over expression (> 9-fold). Combination of moPrP with D-LPS on the mucosal side of the colon induced genes associated with TLR-signaling, apoptosis, and a very strong antibacterial response (> 35-fold Slpi expression). Administration of moPrP on the mucosal side and D-LPS on the serosal side triggered expression of 12 genes related to TLR signaling, apoptosis, and antibacterial responses, as illustrated by overexpression of Slpi by >30-fold. The over expression of Slpi mRNA was further reaffirmed by ELISA and when moPrP was added to the mucosal side and D-LPS on the serosal side, an increased Slpi protein was observed. Application of combined moPrP and D-LPS on the mucosal side significantly increased the Slpi protein. Results of this study demonstrated that moPrP alone or combined with D-LPS affected the expression of various genes related to inflammation, antibacterial, and apoptotic responses.


Subject(s)
Lipopolysaccharides , Prions , Animals , Anti-Bacterial Agents , Colon , Lipopolysaccharides/pharmacology , Male , Mice , Prion Proteins/genetics , Prions/genetics
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