Temperate Forms Research Articles

Preclinical evaluation of novel synthesised nanoparticles based on tyrosine poly(ester amide) for improved targeted pulmonary delivery

Fixed dose combinations (FDCs) incorporating two or three medicines in a single inhaler have been created to enhance patient compliance and hence clinical outcomes. However, the development of dry powder inhalers (DPIs), particularly for FDCs, faces challenges pertinent to formulation uniformity and reproducibility. Therefore, this project aimed to employ nanotechnology to develop a FDC of DPIs for market-leading medicines—fluticasone propionate (FP) and salmeterol xinafoate (SAL)—for asthma management. Nanoaggregates were prepared using a novel biocompatible and biodegradable poly(ester amide) based on the amino acid tyrosine, utilising a one-step interfacial polymerisation process. The produced tyrosine poly (ester amide) drug-loaded nanoparticles were evaluated for content uniformity, PSA, FTIR, TEM, DSC, XRD and aerodynamic performance (in vitro and in vivo). The optimised formulation demonstrated high entrapment efficiency– > 90%. The aerodynamic performance in terms of the emitted dose, fine particle fraction and respirable dose was superior to the carrier-based marketed product. In-vivo studies showed that FP (above the marketed formulation) and SAL reached the lungs of mice in a reproducible manner. These results highlight the superiority of novel FDC FP/SAL nanoparticles prepared via a one-step process, which can be used as a cost-effective and efficient method to alleviate the burden of asthma.

Optimization of a unileg thermoelectric generator by the combination of Taguchi method and evolutionary neural network for green power generation

The performance optimization of thermoelectric generators (TEGs) is crucial for efficiently converting waste heat to green energy. This study analyzes the performance and thermal stress of a unileg thermoelectric module by combining the Taguchi method, analysis of variance (ANOVA), and artificial neural network. The results of the Taguchi method indicate that the leg geometry exerts a negligible effect on output power (OP) and conversion efficiency but significantly affects the thermal stress (TS). The analysis of the objective function (maximum OP-to-maximum TS ratio, denoted by P/S) reveals the optimal configuration results in a P/S value of 0.01255 W‧MPa−1, accompanied by a maximum output power (2.9 W) and thermal stress (232.32 MPa). The maximum thermal stress of the rectangle TE leg (182.29 MPa) is less than that of the triangle (279.85 MPa) by 34.86 %. The Taguchi method, analysis of variance, and artificial neural network have the same sensitivity order on P/S with leg height > leg geometry > copper thickness > ceramic thickness. Furthermore, an evolutionary neural network (ENN) method with five-step optimization from 4000 datasets has been developed to improve machine learning prediction. The average error of P/S value and conversion efficiency from ENN is 1.61 % and 0.35 %, respectively. However, for the ENN predictions, the relative errors of P/S value and efficiency between predictions and simulations are 1.28 % and 0.19 %, respectively. In conclusion, this work has demonstrated the numerical optimization of the performance of unileg TEM for the first time. The use of ENN can predict the performance of TEM precisely, saving running time and markedly reducing computational costs. Moreover, the results are conducive to designing high-performance TEGs with long lifespans.

Complete mitochondrial genome sequences of two ground crickets, Dianemobius fascipes nigrofasciatus and Polionemobius taprobanensis (Orthoptera: Grylloidea: trigonidiidae)

The authors sequenced the complete mitochondrial (mt) genomes of the band-legged ground cricket (Dianemobius fascipes nigrofasciatus Matsumura, 1904) and a temperate form of the lawn ground cricket (Polionemobius taprobanensis Walker, 1869), collected in Japan. The length of the mt genome sequences was 15,354 bp in D. fascipes nigrofasciatus and 16,063 bp in P. taprobanensis. Annotation of the mt genome sequences revealed 13 protein-coding genes, two rRNA genes, and 22 tRNA genes. The orientation of the genes was the same as in other Grylloidea species, and the order was the same as in other Trigonidiidae species. In our phylogenetic analysis, D. fascipes nigrofasciatus formed a clade with D. fascipes collected in China, and the temperate form of P. taprobanensis formed a clade with P. taprobanensis collected in China. Comparison of the numbers of positions with different amino acid residues encoded by the protein-coding genes implied the separate species status of each member of each of the two pairs of ground crickets. The mt genome sequences of D. fascipes nigrofasciatus and P. taprobanensis will contribute to phylogenetic and taxonomic studies of the Trigonidiidae.

Palynofloral Change Through the Paleocene‐Eocene Thermal Maximum in the Bighorn Basin, Wyoming

AbstractTo better understand the effect of the Paleocene‐Eocene Thermal Maximum (PETM) on continental ecosystems, we studied 40 new palynological samples from the Bighorn Basin (BHB), northwestern Wyoming, USA. We see palm and fern abundances increase in the last 20–40 ka of the Paleocene, then dramatically with the onset of the carbon isotope excursion (CIE) defining the base of the PETM. Palynomorphs of plant groups with modern temperate climate distributions are absent from the CIE body, and this is when tropical plants are most diverse and abundant. During the CIE recovery, pollen of mesophytic/wetland plants become more common while tropical taxa persist. In the post‐CIE early Eocene tropical taxa are rare and temperate forms abundant, similar to the late but not latest Paleocene. Changes in the palynoflora are more easily detected if reworked palynomorphs are removed from analyses. We interpret palynofloral changes to indicate warming in the latest Paleocene, rapid warming and drying with the CIE onset, dry tropical climates through the CIE body, a return to wetter floodplains during a very warm CIE recovery, and cooler wet conditions in the post‐PETM early Eocene. These inferences are consistent with geochemical and paleobotanical proxies. Strikingly similar patterns in the palynoflora and megaflora suggest changes in vegetation were a basin‐wide phenomenon. These rapid, climatically forced changes in floral composition occurred without major extinction, perhaps indicating nearby refugia in which plants adapted to cooler and wetter climates persisted through the PETM.

Green Synthesis of Cobalt Oxide Nanoparticles (Co<sub>3</sub>O<sub>4</sub> NPs) using <i>Bauhinia Racemosa</i> (Thiruvachi) Leaves Extract and Its antioxidant, anti-diabetic, and Anti-inflammatory Properties

This study aims to appraise the antioxidant, anti-diabetic, and anti-inflammatory accomplishments of green synthesized cobalt oxide nanoparticles (Co3O4 NPs) mediated by Bauhinia racemosa leaves. Bauhinia racemosa is commonly called ''Thiruvachi' leaf tree in Tamil. The green synthesized Co3O4 NPs are calcinated at 350 °C, then characterized by TG/DTA, UV, FTIR, FL, XRD, DLS, SEM with EDS analysis, TEM, and Supercapacitor performance studies with CV analysis. TGA/DTA result associated with weight loss and exothermic reaction due to desorption of chemisorbed water. FTIR was performed to identify the functional groups of carbonyl, hydroxyl, amine, and protein molecules, which form a layer covering Co3O4 NPs and stabilize the Co3O4 NPs in the medium. The XRD pattern peaks are associated with a poly cubic crystalline form of metallic cobalt oxide nanoparticles. The average grain size of Co3O4 NPs is 36.45 nm. This research focused on Biological studies like antioxidant, anti-diabetic, and anti-inflammatory, total antioxidant measured by phosphomolyptenium reagent with vitamin C as the standard, Anti-diabetics studies carried out by α-amylase inhibition method and anti-inflammatory bustle followed by BSA denaturation technique. The spectral and morphological data confirms the Co3O4 NPs formation. The anti-inflammatory activity showed good results than the antioxidant and anti-diabetic activity.

Synthesis and Electrochemical Properties of SnO2/C Nanocomposites

The SnO2/C nanocomposites were prepared through a facile approach combining sol-gel synthesis with thermal reduction. The XRD, TG, (HR-) TEM, and electrochemical performance tests were used to study the relevance between the physical character and electrochemical properties of the electrode material. As the anode material, the results show that the SnO2/C nanocomposites delivered excellent lithium storage properties (539 mAh g–1 of 100th), compared with the bare SnO2 nanoparticles. It is demonstrated that the preparation of SnO2/C nanocomposites structured can effectively alleviate the particle pulverization caused by volume expansion, effectively shorten the diffusion distance of lithium ions, prevents the aggregation of SnO2 with the carbon layer, and improve the cycle stability of the electrode. Meanwhile, the incorporation of the SnO2 particles suppressed the stack of carbon layer.

Improve the Midpoint Voltage and Structural Stability of Li-Rich Manganese-Based Cathode Material by Increasing the Nickel Content

Lithium-rich manganese is a promising new-generation cathode material for lithium-ion batteries. However, it has the common problems of serious discharge capacity decline, poor rate performance, and faster midpoint voltage decay. In this experiment, a sol-gel method was used to synthesize a high-nickel, lithium-rich layered oxide (1 − x)Li1.2Mn0.54Co0.13Ni0.13O2 − xLiNiO2 (x = 0, 1.0, 2.0, 3.0 and 4.0) that was characterized by XRD, SEM, XPS, TEM, and charge-discharge performance tests. The research results show that increasing Ni content can improve the stability of the material structure and enhance the electrochemical performance of the cathode material. When the LiNiO2 is 0.3, the electrochemical performance is better, the capacity retention rate is 100.3% after 60 cycles at a current density of 0.2 C, and the capacity retention rate for 100 cycles at 0.5 C is 99.0%.

Structural, morphological and supercapacitor applications of SnS nanomaterials prepared in three different types of solvents

In this article, tin sulfide nanoparticles (SnS NPs) are amalgamated by using Polyvinyl pyrrolidone (PVP) + Ethanol named as AR1, Ethylene glycol (EG) named as AR2, and Oleylamine (OA) named as AR3 through the solvothermal method. The amalgamated NPs are characterized by using XRD, FT-IR, UV-DRs, SEM, TEM and Electrochemical performance. The orthorhombic phase of the produced SnS nanoparticles is indicated by XRD patterns. The crystalline size calculated by using the Debye Scherrer equation and Williamson Hall (W-H) plot is correlated to each other. The SEM and TEM images manifestly show that the morphological alterations in the SnS nanoparticles. The FT-IR confirmed the characteristics bands pragmatic at 616 cm−1 and 623 cm−1 for SnS stretching vibrations. The (AR1) electrode had a greater Specific capacitance of 419 F/g than that of AR2 and AR3 electrodes, respectively. The higher Specific capacitance of AR1 calculated using CV and GCDs curves could be attained due to well-developed spherical morphology which produces large surface area and better pore size.

Constructing cycle-stable Si/TiSi2 composites as anode materials for lithium ion batteries through direct utilization of low-purity Si and Ti-bearing blast furnace slag

The large volume expansion and poor conductivity leading to the deterioration of electrochemical performance, is a significant challenge for Si-anode materials for practical applications. Previous researches have indicated that introducing a TiSi2 buffer with high conductivity to form Si/TiSi2 composites can effectively improve the electrochemical performance of Si anode. However, the facile and low-cost synthesis of Si/TiSi2 composites remains challenging. In this study, we propose a novel approach to preparing Si/TiSi2 composites as anode materials for lithium-ion batteries by coupling photovoltaic (PV) silicon waste (simulated using inexpensive low-purity Si (98.8%) in experiments) and metallurgical waste (Ti-bearing blast furnace slag, TBBFS) via a new method combining induction melting and mechanical ball milling. A series of Si/TiSi2 materials were obtained using different ratios of raw materials and investigated using SEM, TEM, XRD, XPS and electrochemical performance tests. The results show that TiSi2 not only acts as a buffer for the bulk expansion of Si, but also improves the electrical conductivity; therefore, the Si/TiSi2 materials exhibit enhanced cycling stability when more TiSi2 is introduced. The sample prepared using a low-purity Si and TBBFS with a mass ratio of 1:3 delivered a reversible capacity of 530 mAh g−1 after 200 cycles at a charge-discharge current density of 800 mA g−1. This work not only provides a new strategy and technology for introducing TiSi2 into Si-based anode materials, but also provides a green and sustainable technical route for the high value-added recycling of Ti-bearing blast furnace slag.

Self-assembly synthesis of dumbbell-like MnPO4·H2O hierarchical particle and its application in LiMnPO4/C cathode materials

The large-scale and efficient synthesis of MnPO4·H2O is an urgent problem to be solved. In this paper, self-assembled dumbbell-shaped MnPO4·H2O particles were successfully synthesized just using KMnO4 and commercial concentrated H3PO4, and then employed as the precursor to prepare LiMnPO4/C composites. The XRD, SEM, TEM, and electrochemical performance tests were used to investigate MnPO4·H2O and the corresponding LiMnPO4/C. The formation mechanism of MnPO4·H2O was discussed. The results showed that temperature and water content have a significant effect on the yield, purity, and morphology of MnPO4·H2O. The synthesized LiMnPO4/C with reduced carbon content at 650 °C delivered a discharge capacity of 109.3 mA h g-1 at 1 C and 104.3 mA h g-1 at 2 C. This green and efficient synthesis method of MnPO4·H2O provides a new idea for the large-scale preparation of LiMnPO4/C cathode materials.

Optimization and design of wide-band and low-noise air-core coil sensor for TEM system

The effective bandwidth and background noise of the sensor are important factors to the performance of TEM, especially in the detection of urban underground space. The limitation of the size of coils further reduces the bandwidth and sensitivity of the sensor, resulting in the distortion of high-frequency signal from ultra-shallow and the loss of weak signal from deep. In order to solve this problem, by establishing the physical model of the induction air-core coil sensor, a method of winding wire which reduces the parasitic parameters of the air-core coil is proposed to improve the bandwidth and sensitivity of system. Combined with theoretical simulation, the components of noise and parasitic parameters of the air-core coil sensor were analyzed, and the system was optimized. An air-core coil sensor with an effective bandwidth of 783 kHz and an equivalent noise of about 2.45 nV/ was obtained. The new sensor effectively improves the detection capability of TEM system for high-frequency secondary field signal, which has positive significance for the application of TEM in urban underground space.

Rational design of electroactive redox enzyme nanocapsules for high-performance biosensors and enzymatic biofuel cell

The potential application of biodevices based on enzymatic bioelectrocatalysis are limited by poor stability and electrochemical performance. To solve the limitation, modifying enzyme with functional polymer to tailor enzyme function is highly desirable. Herein, glucose oxidase (GOx) was chosen as a model enzyme, and according to the chemical structure of GOx cofactor (flavin adenine dinucleotide, FAD), we customize a biomimetic cofactor containing vinyl group (SFAD) for GOx, and prepared an GOx nanocapsule via in-situ polymerization. The characterization of particle size distribution, TEM, fluorescence and electrochemical performance indicated the successful formation of electroactive GOx nanocapsule with SFAD-containing polymeric network (n (GOx-SFAD-PAM)). The network can act as an electronic “highway” to link the active site with electrode, with capability to accelerate electron transfer as well as enhanced GOx stability. Further investigation of bioelectrocatalysis shows that n (GOx-SFAD-PAM)-based biosensor has low detection potential (−0.4 vs. Ag/AgCl), high sensitivity (64.97 μAmM−1cm−2), good anti-interference performance, quick response (3⁓5s) and excellent stability, and that n (GOx-SFAD-PAM)-based enzymatic biofuel cell (EBFC) has the high maximum power density (1011.21 μWcm−2), which is a 385-fold increase over that of native GOx-based EBFC (2.62 μWcm−2). This study suggests that novel enzyme nanocapsule with electroactive polymeric shell might provide a prospective solution for the performance improvement of enzymatic bioelectrocatalysis-based biodevices.

Miocene-Pliocene biochronology of the Obregón Basin and it's bearing on the evolution of the Proto-Gulf of California

The content of dinoflagellates, foraminifera, and calcareous nannofossils in cuttings samples from the Cajeme-1 well defines the age and depositional environments of ~1500 m of marine sediments drilled in the Obregón Basin, in the south of Sonora. The base of the drilled column is composed of actinolite hornfels dated as 43 ± 2 Ma, which underlies ~500 m of pyroxene basalts, correlatable with local late Miocene extrusives. The sedimentary strata are deposited unconformably on top of the basalts, and its paleobathymetric evolution indicates that the sedimentary column represents a marine stratigraphic sequence that starts with late Miocene marine evaporites that grade upwards to upper bathyal shales. The upper part of the sequence represents a general shallowing to inner neritic, transitional, and even continental environments in the Pliocene to Holocene interval. Marine microfossil assemblages represent a mixed provenance, from subtropical and temperate forms, and dinoflagellate assemblages indicate deposition in a marine basin with a significant terrigenous influx and no evidence of upwellings. The Obregón Basin represents marine deposition on the Proto-Gulf starting sometime between 11 and 8 Ma and, reaching bathyal depths (150–500 m) at approximately 8 Ma. Marine sedimentation in the Proto-Gulf, however, seems to have started earlier to the north, in the Tiburon and Wagner basins, where marine microfossils indicate an age older than 11.2 Ma. By late Miocene (~6 Ma), there were marine environments to the north, from the Obregón Basin to the Salton Sea area. The marine Obregón Basin represents the oldest marine deposits in the central and southern parts of the Gulf of California.

Preparation of Li4Ti5O12/C composite by one-step solid state method

The Li4Ti5O12/C composites were synthesized by one-step solid-phase reaction using metatitanic acid, lithium carbonate and sucrose as raw materials. The effects of the molar ratio of lithium to titanium, calcining temperature, calcination time, and sucrose content on the structure of Li4Ti5O12/C composites were studied. XRD, SEM, TEM and electrochemical performance tests were used to characterize the results. The results showed that n(Li):n(Ti) = 0.85, calcination temperature was 750 °C, calcination time was 6 h, and the sucrose addition amount was 30% of the total mass of raw materials. Under the conditions, the pure Li4Ti5O12/C composites can be synthesized. The particles are uniform, the particle size is 0.1–1 μm, and the carbon envelopment is better. The specific capacity is up to 163.94 mAh/g at 0.1 C rate, and the theoretical specific capacity is 175 mAh/g very close.

Preparation and properties of TiO2/illite composites synthesized at different hydrothermal pH values

In this experiment, The TiO2/illite composites were synthesized by a simple hydrothermal method, taking Ti(SO4)2 as Ti precursor and illite as substrate. The as-prepared composites were characterized by XRD, FT-IR, BET, SEM, TEM and photocatalytic performance. The results show that TiO2 particles do not enter the interlayer of the illite because the (0 0 1) diffraction peak of illite in the composites does not shift. Illite and TiO2 are connected by Si-O-Ti and Al-O-Ti bond and the presence of illite can inhibit the transition from anatase to rutile. Moreover, the dispersion of TiO2 particles in the composite is obviously improved. When the pH value is 1.5, the photocatalytic performance of the composites is the best. The degradation rate of methyl orange (MO) solution can reach 73.4% after 8 h visible light irradiation and 93.6% after 40 min ultraviolet light irradiation, which is better than P25.

Effect of drying temperature on properties of lithium-rich manganese-based materials in sol-gel method

A lithium-rich manganese-based cathode material Li1.2Mn0.54Ni0.13Co0.13O2 is restricted by the first charge and discharge efficiency and the cycle retention rate. In this paper, the effects of different drying temperatures on the comprehensive properties of Li1.2Mn0.54Ni0.13Co0.13O2 materials in sol-gel method were studied systematically. Through XRD, SEM, TEM, and electrochemical performance tests, it was found that the prepared materials have the best structure and properties when the drying temperature is 140 °C. The first discharge specific capacity is as high as 262.5 mAh/g in a voltage of 2.0–4.8 V. After circulating 100 cycles at a magnification of 0.5 C and 2 C, the capacity retention ratios were 80.46% and 84.14%, respectively.

Li0.95Na0.05MnPO4/C nanoparticles compounded with reduced graphene oxide sheets for superior lithium ion battery cathode performance

Sodium-substituted LiMnPO4/C/reduced graphene oxide (LNMP@rGO) was synthesized in this study via freeze drying and carbon thermal reduction method with graphene oxide as carbon source. Sodium ion doping is optimized and rGO effects are evaluated by XRD, SEM, TEM, BET, Raman, and electrochemical performance measurements. Well-distributed nanoparticles with average size of ~50 nm are evenly distributed on the surface or intercalation between rGO layers, resulting in a porous ion/electronic conductive network. Compared to 122.3 mA h g−1 in unmodified LNMP, the best LNMP@rGO (20 mg rGO) exhibits an excellent initial discharge capacity of 150.4 mA h g−1 at 0.05 C at 122.9% of the initial capacity. The capacity retention rate is 95.8% of the initial capacity after 100 cycles at 1 C. Capacity of 101.2 mA h g−1 is preserved even at rates as high as 10 C.

The effect of oxidation and resulfidation on (Ni/Co)MoS2 hydrodesulfurisation catalysts

The effect of a sequential oxidation and resulfidation treatment on γ-Al2O3 supported (Ni/Co)MoS2 catalyst nanoparticles was investigated using (HR)TEM, XPS, and thiophene HDS catalytic performance experiments. Analysis of the HRTEM images revealed that, after initial sulfidation and oxidation, the resulfidation treatment restored the original slab length or increased it. The chemical composition of the samples, as determined by XPS, also slightly changed: the concentration of oxidic species increased, especially for the Ni promoter atoms. Comparing the catalytic HDS activity of the samples before and after the oxidation-resulfidation treatment showed that the catalysts were more than 20% more active after resulfidation. This increase in HDS activity is ascribed to a redistribution of the (Ni/Co)MoS2 slabs during the second sulfidation treatment, indicating a size effect.

Application of FIB in the preparation of TEM specimens of experimental supercoarse WC-Co(Ni) composites

Advances in TEM's performance as well as in materials being investigated require the relevant improvement in sample preparation technology. For a long period of time TEM investigations of metals have been successfully performed using the electrochemical jet polishing method for the sample preparation, i.e. thinning. This classical approach has proved to be unsatisfactory in the case of electrically not conductive and/or multiphase materials – for instance various kinds of ceramics and composites. A milestone in solving this problem has been an elaboration of ion milling. Overcoming certain disadvantages of this technology, mainly sample damage, as well as providing site specificity of the sampling procedure, has been achieved owing to the onset and development of the focused ion beam (FIB) method. The current paper presents the authors' own experience in the preparation of TEM specimens of conventional WC-Co type and experimental WC-Ni based supercoarse sintered carbides. These metal matrix composites consist of large (ca. 10 μm) tungsten carbide particles and a binding metal phase (cobalt or nickel based). Because of the pronounced microstructural, mechanical and electrochemical inhomogeneity, as well as the size of hard WC particles, traditional (mechanical, jet polishing, electrochemical) procedures proved to be totally inadequate. Therefore multi stage lift-out procedure employing a focused beam of gallium ions of various energy (in situ lift-out of the sample plus H-bar geometry final thinning) and argon ion polishing aimed at the removal of the damaged (defected and amorphous) layer has been elaborated and successfully applied. A large number of defects in the WC particles (dislocations, stacking faults) and within the matrix areas (dislocations, microtwins) as well as high quality of the WC-metal matrix interfaces were found.

Binder and conductive additive free silicon electrode architectures for advanced lithium-ion batteries

This manuscript presents binder and conducting additive free Silicon nanoparticles (Si-NPs) as anodes for lithium-ion batteries. The Si-NPs are pressure embed onto copper foil current collector without using any organic binder or conductive carbon additive. It presents physical and structural studies by XRD, SEM, Raman, TEM and electrochemical performance of Si-NPs by electrochemical impedance spectroscopy and galvanostatic charge-discharge cycling. Binder-free Si-NP electrodes exhibit an initial reversible capacity of 950 mAh g−1 at C/10 rate and more than 650 mAh g−1 during 500 cycles at C/2 rate. The electrodes shows excellent rate capability (800 mAh g−1 at 5 C rate) and cycling stability, because of available free space for volume change during cycling of silicon NPs without pulverization. The binder-free anode fabrication enables Si-NPs to obtain the real capacity of silicon without any interference of capacity contribution from composite materials.