Production Rate Research Articles

Membrane‐Free Electrocatalytic Co‐Conversions of PBS Waste Plastics and Maleic Acid into High‐Purity Succinic Acid Solid

AbstractPlastic pollution, an increasingly serious global problem, can be addressed through the full lifecycle management of plastics, including plastics recycling as one of the most promising approaches. System design, catalyst development, and product separation are the keys in improving the economics of electrocatalytic plastics recycling. Here, a membrane‐free co‐production system was devised to produce succinic acid (SA) at both anode and cathode respectively by the co‐electrolysis of polybutylene succinate (PBS) waste plastics and biomass‐derived maleic acid (MA) for the first time. To this end, Cr3+‐Ni(OH)2 electrocatalyst featuring much enhanced 1,4‐butanediol (BDO) oxidation reaction (BOR) activity has been synthesized and the role of doped Cr has been revealed as an “electron puller” to accelerate the rate‐determining step (RDS) in the Ni2+/Ni3+ cycling. Impressively, an extra‐high SA production rate of 3.02 g h−1 and ultra‐high apparent Faraday efficiency towards SA (FEapparent=181.5 %) have been obtained. A carbon dioxide‐assisted sequential precipitation approach has been developed to produce high‐purity SA and byproduct NaHCO3 solids. Preliminary techno‐economic analysis demonstrates that the reported system is economically profitable and promising for future industrial applications.

Investigation into the hydrogen inhibition mechanism of Platycladus orientalis leaf extract as a biodegradation inhibitor for waste aluminum-silicon alloy dust in wet dust collectors

This study investigates the risk of hydrogen explosion caused by waste metal dust encountering water in wet dust collectors. It proposes using renewable plant extracts to suppress hydrogen evolution from aluminum-silicon (Al-Si) alloy dust, aiming to achieve intrinsically safer production. Platycladus orientalis leaf extract (POLE) was prepared using water as a solvent. Hydrogen inhibition experiments, material characterization, and theoretical calculations were conducted to evaluate the effect of POLE on waste Al-Si dust. The inhibition experiments demonstrated that POLE exhibits excellent inhibitory performance. At a POLE concentration of 2.0 g/L, the hydrogen inhibition efficiency reaches 97.71 % after 22 h, with a reaction rate constant of 8.9708 × 10−5, approaching zero. This efficiency remained stable over 5 days. POLE formed a uniform, dense protective film on the Al-Si dust surface, with a contact angle of 99.23°. FTIR spectra revealed absorption peaks corresponding to POLE functional groups and Al-O bonds, indicating that successfully adsorption of POLE through both physical and chemical interactions. Finally, theoretical calculations were performed to further explain the hydrogen inhibition mechanism of POLE, supplementing and confirming the characterization data. This study inhibited hydrogen production from waste dust, offering a new approach to enhancing the hydrogen production rate from recycled Al scraps.

Improved Nitrate-to-Ammonia Electrocatalysis through Hydrogen Poisoning Effects.

Electrochemical conversion from nitrate to ammonia is a key step in sustainable ammonia production. However, it suffers from low productive efficiency or high energy consumption due to a lack of desired electrocatalysts. Here we report nickel cobalt phosphide (NiCoP) catalysts for nitrate-to-ammonia electrocatalysis that display a record-high catalytic current density of -702±7 mA cm-2, ammonia production rate of 5415±26 mmol gcat-1 h-1 and Faraday efficiency of 99.7±0.2 % at -0.3 V vs. RHE, affording the estimated energy consumption as low as 22.7 kWh kgammonia-1. Theoretical and experimental results reveal that these catalysts benefit from hydrogen poisoning effects under low overpotentials, which leave behind catalytically inert adsorbed hydrogen species (HI*) at Co-hollow sites and thereupon enable ideally reactive HII* at secondary Co-P sites. The dimerization between HI* and HII* for H2 evolution is blocked due to the catalytic inertia of HI* thereby the HII* drives nitrate hydrogenation timely. With these catalysts, the continuous ammonia production is further shown in an electrolyser with a real energy consumption of 18.9 kWh kgammonia-1.

Synergistic Active Heterostructure Design for Enhanced Two Electron Oxygen Reduction via Chemical and Electrochemical Reconstruction of Heterosulfides.

Transition metal sulfides, particularly heterostructures, represent a promising class of electrocatalysts for two electron oxygen reduction (2e- ORR), however, understanding the dynamic structural evolution of these catalysts during alkaline ORR remains relatively unexplored. Herein, NiS2/In2.77S4 heterostructure was synthesized as a precatalyst and through a series of comprehensive ex-situ and in-situ characterizations, including X-ray absorption spectroscopy, Raman spectroscopy, transient photo-induced voltage measurements, electron energy loss spectroscopy, and spherical aberration-corrected electron microscopy, it was revealed that nickel/indium (oxy)hydroxides (NiOOH/In(OH)3) could be evolved from the initial NiS2/In2.77S4 via both electrochemical and chemical-driven methods. The electrochemical-driven phase featured abundant bridging oxygen-deficient [NiO6]-[InO6] units at the interfaces of NiOOH/In(OH)3, facilitating a synergistic effect between active Ni and In sites, thus enabling an enhanced alkaline 2e- ORR capability than that of chemical-driven process. Remarkably, electrochemically induced NiOOH/In(OH)3 exhibited exceptional performance, achieving H2O2 selectivity of >90% across the wide potential window (up to 0.4 V) with a peak selectivity of >99%. Notably, within the flow cell, a current density exceeding 200 mA cm-2 was sustained for over 20 h, together with an impressive Faradaic efficiency of approximately 90% and a hydrogen peroxide production rate surpassing 4 mol g-1 h-1.

Precisely Constructing Molecular Junctions in Hydrogen‐Bonded Organic Frameworks for Efficient Artificial Photosynthetic CO2 Reduction

AbstractThe development of artificial photocatalysts to convert CO2 into renewable fuels and H2O into O2 is a complex and crucial task in the field of photosynthesis research. The current challenge is to enhance photogenerated charge separation, as well as to increase the oxidation capability of materials. Herein, a molecular junction‐type porphyrin‐based crystalline photocatalyst (Ni‐TCPP‐TPyP) was successfully self‐assembled by incorporating a nickel porphyrin complex as a reduction site and pyridyl porphyrin as an oxidation site via hydrogen bonding and π–π stacking interactions. The resulting material has a highly crystalline structure, and the formation of inherent molecular junctions can accelerate photogenerated charge separation and transport. Thus, Ni‐TCPP‐TPyP achieved an excellent CO production rate of 309.3 μmol g−1 h−1 (selectivity, ~100 %) without the use of any sacrificial agents, which is more than ten times greater than that of single‐component photocatalyst (Ni‐TCPP) and greater than that of the most organic photocatalysts. The structure‐function relationship was investigated by femtosecond transient absorption spectroscopy and density functional theory calculations. Our work provides new insight for designing efficient artificial photocatalysts, paving the way for the development of clean and renewable fuels through the conversion of CO2 using solar energy.

Improvement of photocatalytic CO2 reduction with conjugated organic polymers by rational modulation of donor, acceptor and bonding method.

The use of metal-free catalysts to convert CO2 into valuable chemicals is very challenging. Here, we synthesized a conjugated organic polymer (TpTf-1) featuring 2,4,6-Triphenyl-1,3,5-Triazine as the acceptor unit, triphenylamine as the donor unit, and vinylidene bond as the linkage. The local structure of donor-acceptor (D-A) forms an intramolecular electric field that can promote the separation of photogenerated electrons and charges, meanwhile, the vinylidene bond can further change the charge distribution to promote exciton dissociation. Without the use of photosensitizers, the TpTf-1 exhibits outstanding selectivity of CO of up to 91.96%, with a production rate of 45.2 μmol·g-1·h-1 at visible light, which is 3.4-fold than TaTf-1 with the same D-A structure but linking in imine bond and is 2.8-fold than TpTf-2 linking in vinylidene bond but with a different donor unit. Moreover, TpTf-1 has a CO production rate of up to 117.3 μmol·g-1·h-1 under full wavelength light irradiation.

Membrane-Free Electrocatalytic Co-Conversions of PBS Waste Plastics and Maleic Acid into High-PuritySuccinic Acid Solid.

Plastic pollution, an increasingly serious global problem, can be addressed through the full lifecycle management of plastics, including plastics recycling as one of the most promising approaches. System design, catalyst development, and product separation are the keys in improving the economics of electrocatalytic plastics recycling. Here, a membrane-free co-production system was devised to produce succinic acid (SA) at both anode and cathode respectively by the co-electrolysis of polybutylene succinate (PBS) waste plastics and biomass-derived maleic acid (MA) for the first time. To this end, Cr3+-Ni(OH)2 electrocatalyst featuring much enhanced 1,4-butanediol (BDO) oxidation reaction (BOR) activity has been synthesized and the role of doped Cr has been revealed as an "electron puller" to accelerate the rate-determining step (RDS) in the Ni2+/Ni3+ cycling. Impressively, an extra-high SA production rate of 3.02 g h-1 and ultra-high apparent Faraday efficiency towards SA (FEapparent=181.5%) have been obtained. A carbon dioxide-assisted sequential precipitation approach has been developed to produce high-purity SA and byproduct NaHCO3 solids. Preliminary techno-economic analysis demonstrates that the reported system is economically profitable and promising for future industrial applications.

Modelling the ejection of primary aerosols during the fast pyrolysis of biomass anisotropic particles

A model for the fast pyrolysis of anisotropic biomass particles is presented which considers bubbling dynamics within the liquid intermediate phase (metaplast) and aerosol ejection from this phase. The model employs the population balance equation and the method of moments to estimate the production rate and resultant size distribution of aerosol ejections, incorporating a detailed CRECK reaction mechanism, and considers the effect of anisotropic biomass microstructure on the intraparticle transport of mass and energy. This study investigates the impact of particle size, heating rate (heat transfer coefficient), and lignocellulosic composition on aerosol ejection. The model predicts that, at high heating rates (convective heat transfer coefficient of 359 W/m2.K), aerosols can contribute over 20% to the heavy fraction yield in bio-oil for small particles (1 mm diameter, 4 mm length). The model can predict aerosol size distribution and surface area, indicating an average size of 20 μm for bubbles and 5 μm for aerosols during increased bubble production and aerosol ejection rates. These findings are consistent with prior experimental results and provide essential information for future modeling of extra-particle reactions of the aerosols as they progress through the reactor.

Cu2WS4 with high-exposure {0 0 1} surfaces promotes efficient charge separation in ZnIn2S4

The spatial segmentation of photogenerated carriers is crucial for achieving efficient photocatalytic H2 production (PHP) rates in photocatalyst. Design studies of crystalline catalyst facets and selective morphology control can facilitate the development of catalysts that expose more advantageous active facets. Herein, Cu2WS4/ZnIn2S4 composites are constructed by growing ZnIn2S4 nanosheets in situ on Cu2WS4 with largely exposed {001} surface. Experiments and density functional theory calculations demonstrate that the electrons of ZnIn2S4 flowed to the {001} surface of Cu2WS4, and the holes vectorially migrated to the {101} surface, during the reaction process, resulting in efficient spatial separation of the photogenerated carriers. The Cu2WS4/ZnIn2S4 achieves a PHP rate of 23.67 mmol g−1 h−1, 13.44-fold increase compared with pure ZnIn2S4. This report combines the advantages of the high-energy activity of the Cu2WS4 {001} surface to morphologically control the ratio of the {001}/{101} surfaces so that ZnIn2S4 can contact a larger area of the {001} surface. Furthermore, under the influence of crystallographic effects on the {001} and {101} surfaces, electrons and holes of ZnIn2S4 are transferred to different crystalline facets, promoting the redox reaction. This paper provides effective ideas for the rational design of photocatalysts with efficient carrier space separation.

Trends and insights in animal and biomedical research: A 5-year scientometric analysis of orthodontic peer-reviewed journals

Biomedical research plays a critical role in advancing orthodontic innovations by identifying new targets for therapeutic interventions and developing more effective, personalized orthodontic treatment. This study evaluates the major contributors and trends in animal-related orthodontic research over the past 5 years (2017-2023). All animal-related studies published in the eight orthodontic journals listed in the 2022 Journal Citation Reports between January 2017 and June 2023 were retrieved from the Web of Science Core Collection. After examination, the following bibliometric data were extracted from each article: title, authors, affiliations, geographic origin, year of publication, journal name, and keywords. Multiple bibliometric software packages including Biblioshiny R-package software, Datawrapper, and Datasmith were used to analyze different bibliometric outcomes. A total of 3669 articles were screened from which 266 were selected and included in the analysis. The annual growth rate of production exhibited a decline of 11.18%. Most of the included studies focused on orthodontic tooth movement (32.3%), mainly utilizing rat models (50%). Although the United States accounted for the highest number of publications (n = 236), the trend in funded research showed a decreasing trajectory over time, with notably limited funding from the National Institutes of Health. This study reveals a declining trend in overall animal-related orthodontic research, highlighted by a significant decrease in National Institutes of Health funding over time. To address this gap, academic institutions and professional organizations should support initiatives fostering biomedical orthodontic research.

Nitrogen-doped ZnIn2S4 and TPA multi-dimensional synergistically enhance photocatalytic hydrogen production

To alleviate the environmental pollution and energy crisis caused by the excessive use of fossil fuels, photocatalytic water splitting to produce hydrogen is an important way to solve energy and environmental problems. Here, Nitrogen-doped ZnIn2S4 (N-ZIS) composite tungsten-based polyoxometalate (TPA) composites (denoted as N-ZIS/TPA) were synthesized by a one-step solvothermal method. The introduction of N3– instead of S2− in ZIS changes the internal electron arrangement of ZIS, improves the electronegativity of ZIS, and is conducive to the surface adsorption of positively charged H*. At the same time, the impurity energy level is generated at the valence band position, which narrows the band gap and broadens the light absorption range, thereby promoting photocatalytic hydrogen production. After compounding, due to the adjustable redox properties of TPA itself, the internal W6+ part is reduced to W4+, resulting in the coexistence of W6+ and W4+ in the composite material, which fully verifies the flow of interface electrons from N-ZIS to TPA. The close contact between N-ZIS and TPA and the built-in electric field’s driving force help achieve efficient interfacial charge transfer. At the same time, W6+/W4+ redox pairs were introduced to accelerate the separation of photogenerated electrons and holes. The photocatalytic hydrogen production rate of the best sample 1N-ZIS/TPA-15 is as high as 17345.53 μmol·g−1·h−1, which is 2.92 times that of N-ZIS (5940.08 μmol·g−1·h−1) and 8.03 times that of ZIS (2159.22 μmol·g−1·h−1). This study explores the design and construction of efficient s-type heterojunctions by adjusting the energy band position of ZnIn2S4 as a new strategy in the field of photocatalytic hydrogen production.

Developing flame retardant, smoke suppression and self-healing polyvinyl alcohol composites by dynamic reversible cross-linked chitosan-based macromolecule

With the increasing threat of white pollution to the public health and ecosystem, functional materials driven by green and sustainable biological macromolecule are attracting considerable attention. Inspired by the double-helix structure of DNA, a P–B–N ternary synergistic chitosan-based macromolecule (PBCS) was constructed to prepare flame retardant, smoke suppression and self-healing polyvinyl alcohol composite (PVA@PBCS) via dynamic reversible interactions. The limiting oxygen index value of PVA@PBCS increased from 19.6 % to 28.7 %, whereas the peak heat release rate and total heat release decreased by 47.04 % and 43.37 %, respectively. Besides, the peak smoke production rate and total smoke production of PVA@PBCS also decreased by 45.31 % and 54.98 %. With the presence of borate ester-based covalent and multiple hydrogen bonds, the tensile strength and elongation at break of PVA@PBCS increased by 19.50 % and 16.85 % compared to the control sample, and the healing efficiency for tensile strength and elongation at break was as high as 93.86 % and 90.57 %, respectively. This work developed an eco-friendly and effective scenario for fabricating flame retardant and smoke suppression PVA materials, stimulating the substantial potential of chitosan-based biomacromolecule and dynamic reversible cross-linked tactics in self-healing field.

Light-Driven Reverse Water Gas Shift Reaction with 1000-H Stability on High-Entropy Alloy Catalysts.

Highly stable and active catalysts are of significant importance and a longstanding challenge for a number of industrial chemical transformations. Here, motivated by the principle of the high entropy-stabilized structure, high-entropy alloy-loaded porous TiO2 as an efficient and sintering-resistant catalyst for the light-driven reverse water gas‒shift reaction without external heating is synthesized. The optimized CoNiCuPdRu/TiO2 catalyst exhibits a long-term stability of 1000h (1.23molgmetal -1h-1 CO production rate, >99% high selectivity). In situ characterizations confirm that the slow diffusion effect of high-entropy alloys endows the catalyst with excellent structural stability. The CO adsorption measurements and theoretical calculations consolidate that the hydrogen surface coverage weakens CO adsorption on the catalyst surface. Two major problems of catalyst deactivation - sintering and poisoning, are handled in one case, which synergistically enable unparalleled stability. This work provides new guidance for the rational design of ultradurable harsh-condition operation catalysts for industrial catalysis.

Temperature differentially regulates estuarine microbial N2O production along a salinity gradient

Nitrous oxide (N2O) is atmospheric trace gas that contributes to climate change and affects stratospheric and ground-level ozone concentrations. Ammonia oxidizers and denitrifiers contribute to N2O emissions in estuarine waters. However, as an important climate factor, how temperature regulates microbial N2O production in estuarine water remains unclear. Here, we have employed stable isotope labeling techniques to demonstrate that the N2O production in estuarine waters exhibited differential thermal response patterns between nearshore and offshore regions. The optimal temperatures (Topt) for N2O production rates (N2OR) were higher at nearshore than offshore sites. 15N-labeled nitrite (15NO2-) experiments revealed that at the nearshore sites dominated by ammonia-oxidizing bacteria (AOB), the thermal tolerance of 15N-N2OR increases with increasing salinity, suggesting that N2O production by AOB-driven nitrifier denitrification may be co-regulated by temperature and salinity. Metatranscriptomic and metagenomic analyses of enriched water samples revealed that the denitrification pathway of AOB is the primary source of N2O, while clade II N2O-reducers dominated N2O consumption. Temperature regulated the expression patterns of nitrite reductase (nirK) and nitrous oxide reductase (nosZ) genes from different sources, thereby influencing N2O emissions in the system. Our findings contribute to understanding the sources of N2O in estuarine waters and their response to global warming.

Integrated optimization for X-bar control chart, preventive maintenance and production rate

There are close relationships among statistical process control, maintenance, and production that have not fully explored in existing studies. In this study, we propose an economic model for jointly optimizing the X-bar control chart, preventive maintenance, and production rate. Unlike conventional studies relying on known failure rate functions, we employ a Gamma process to describe the system's deterioration. This approach allows us to consider not only the relationship between the production rate and the deterioration rate but also a broad range of deterioration scenarios and failure modes in the integrated optimization. After calculating the failure probability at each time point, we propose a recursive method to derive the production revenue, process control costs, and quality losses. This approach explores the close inner relationship between the production rate, deterioration, process monitoring and maintenance. Subsequently, we establish an optimization model aimed at maximizing the profit rate within a renewal cycle. The decision variables of this model include the production rate, control chart coefficient, sample size, length of the first sampling interval, and number of sampling intervals. Finally, we use a case study to illustrate the effectiveness and validity of our proposed model by identifying and explaining the interactions between production rate, deterioration, process control and maintenance.

In-situ construction of Bi-MOF-derived S-scheme BiOBr/CdIn2S4 heterojunction with rich oxygen vacancy for selective photocatalytic CO2 reduction using water

In this study, a highly selective MOF-BiOBr/CdIn2S4 (MOF-BiOBr/CIS) heterostructure with CdIn2S4 nanosheets grown in situ on the tubular structure derived from Bi-MOF-based BiOBr was successfully constructed using a hydrothermal method. Under simulated solar light without sacrificial or photosensitizing agents, the 20-MOF-BiOBr/CIS composite exhibited excellent photocatalytic CO2 performance, achieving production rates of 30.18 μmol‧g−1‧h−1 for CO and 1.50 μmol‧g−1‧h−1 for CH4. Compared to pure MOF-BiOBr and CdIn2S4, the CO production rates were increased by approximately 9 and 116 times, respectively. It was revealed that the 20-MOF-BiOBr/CIS composite with rich oxygen vacancy exhibited close interfacial contact and efficient charge transfer. The formation of MOF-BiOBr/CdIn2S4 heterojunction thereby provided efficient CO2 photocatalytic reduction. The CO selectivity of 20-MOF-BiOBr/CIS reached 83.4 %, and the MOF-BiOBr/CIS heterojunction exhibited good stability over multiple cycles. Furthermore, a mechanism for enhanced photocatalytic CO2 reduction by the MOF-BiOBr/CIS heterojunction was also proposed.

Photoelectrolysis of glucose and fructose containing solution in PGM-free cells for hydrogen and valuable chemicals production

This study investigates the reforming of glucose and fructose by photoelectrolyis, employing TiO2 NTs photoanodes for the selective oxidation of the carbohydrates and Ni foam as cathode. TiO2 NTs with different structural features were grown on Ti felt via anodizing and annealing to promote their crystallization.These electrodes were tested in aqueous solutions at three different pH values (i.e., 2, 7, and 12) both without and with the addition of biomass. When biomass was present, the hydrogen production rate increased, reaching faradic efficiencies (FEs) ∼ 100% in spite of the use of undivided cell, allowing the simultaneous production of valuable partial oxidation compounds, such as gluconic acid (GA) and formic acid (FA), with FEs of 24% and 55% respectively, and overall quantum yields of 5.67% and 4.36% respectively. The photoanodes used demonstrated high mechanical and chemical stability under all the tested conditions, with electrode performance remaining consistent over time, allowing the reuse of the same electrode for a not limited number of runs after a mild cleaning step.The results demonstrated that this photoelectrocatalytic (PEC) process is promising for both biomass valorization and H2 production.

​The structural regulation of photosensitive unit and conjugation in COFs for efficient photocatalytic H2 evolution.

The photosensitive unit and conjugation play a significant role in photocatalytic performance of covalent organic frameworks (COFs). In this work, a series of COFs that introduced the phenyl phenanthridine as photosensitive unit with different planarity of linkages were synthesized and the common regulation between them for photocatalysis hydrogen evolution reaction (HER) was also studied. The results indicate that DHTB-PPD, with 2/3 planarity linkages (β-ketoenamine/imine is 2/3) and the phenyl phenanthridine as building blocks, shows the narrowest bandgap and the strongest charge separation efficiency. Therefore, it shows the highest H2 production rate of 12.13 mmol g-1 h-1. The optimal photocatalytic efficiency of DTHB-PPD can be attributed to the combined effect of the photosensitive unit and the long-range ordering of the COF skeleton. According to The Density Functional Theory (DFT), the O site on β-ketoamine is the most possible H2 generation site, but the photocatalytic efficiency of TP-PPD, with the highest skeletal conjugation and the highest proportion of β-ketoamine is not the most efficient photocatalyst, indicating that the long-range ordering of COFs is important on photocatalytic performance. Thus, these findings provide valuable guidance for the structural design of COFs photocatalysts.

Designing 2D carbon dot nanoreactors for alcohol oxidation coupled with hydrogen evolution

The coupled green energy and chemical production by photocatalysis represents a promising sustainable pathway, which poses great challenges for the multifunction integration of catalytic systems. Here we show a promising green photocatalyst design using Cu-ZnIn2S4 nanosheets and carbon dots as building units, which enables the integration of reaction, mass transfer, and separation functions in the nano-space, mimicking a nanoreactor. This function integration results in great activity promotion for benzyl alcohol oxidation coupled H2 production, with H2/benzaldehyde production rates of 45.95/46.47 mmol g−1 h−1, 36.87 and 36.73 times to pure ZnIn2S4, respectively, owning to the enhanced charge accumulation and mass transfer according to in-situ spectroscopies and computational simulations of the built-in electrical field. Near-unity selectivity of benzaldehyde is achieved via the effective separation enabled by the Cu(II)-mediated conformation flipping of the intermediates and subsequent π-π conjugation. This work demonstrates an inspiring proof-of-concept nanoreactor design of photocatalysts for coupled sustainable systems.

Optimization of donor cell production for somatic cell nuclear transfer in the critically endangered Vietnamese Ỉ pig

We aimed to establish efficient donor cells to produce piglets by somatic cell nuclear transfer (SCNT) of the endangered Vietnamese Ỉ pig. In Experiment 1, we assessed the effects of cell passages on the in vitro development of SCNT embryos. Cells with five and six passages showed significantly cleaved and blastocyst formation rates (86.72 and 86.64; 35.68 and 35.51, respectively, P < 0.05). The highest average total cell number per blastocyst was observed in groups of cells with five and six passages (50.45 and 50.18, respectively). Experiment 2 was performed to assess the sex of donor cells on the subsequent development of SCNT embryos. There was no significant difference in the cleaved and blastocyst formation rates, and the average total cell between female and male groups (86.51 % vs 86.94 % and 35.31 % vs 35.08 %, 50.29 % vs 50.67 %, respectively, P > 0.05). Experiment 3 was performed to assess the effect of cell lines on the development of SCNT embryos. Our results showed no significant difference in the success rate of fibroblast nuclear transfer into recipient oocytes, the cleaved and blastocyst formation rates, and the average total cell number per blastocyst among the cell lines 6004, 9154, 9155, 9156 and 9157 (P > 0.05). Experiment 4 was performed to assess the ability of SCNT embryos to induce pregnancy and to develop term. SCNT embryos were produced from Ỉ fibroblast cells established based on the results of Experiments 1, 2 and 3. Transfer of blastocyst stage embryos into 19 recipients (100–120 embryos in each) resulted in 14 pregnancies, in which 8 pregnant females terminated on Day 22–42 and 6 others produced 20 cloned piglets from donor cells of a female pig but 5 piglets died before birth and 15 healthy cloned piglets. However, 3 out of 15 healthy piglets died of unknown causes within 24h of birth and 3 out of 15 healthy piglets died at 3–5 days of age due to diarrhoea, 9 out of 15 healthy piglets are now 3 months of age. Finally, we established a protocol for the donor cell production which enabled the production of the endangered Ỉ pig embryos by SCNT and maximized blastocyst production rate by more than 35 % and pregnant rate after the transfer of cloned Ỉ pig embryos to recipients at 73.68 % for the first time in Vietnam.