Fertilization as the most critical factor affecting yield response and agronomic efficiency of phosphorus in Chinese rice production: evidence from multi-location field trials.

BACKGROUND: Efficient utilization of phosphorus (P) has been a major challenge for sustainable agriculture. However, the responses of fertilizer rate, region, soil properties, cropping systems and genotypes to P have not been investigated comprehensively and systematically. RESULTS: A comprehensive analysis of 9863 fertilizer-P experiments on rice cultivation in China showed that rice yield  increased first and then fell down with the addition of P fertilizer, and the highest yield of 7963 kg ha-1 was observed under 100% P treatment. Under 100% P treatment, the yield response of applied P (YRP ) and agronomic efficiency of applied P (AEP ) were 12.8% and 30.1 kg ha-1 , respectively. Lower soil pH (< 5.5) and organic matter (< 30.0 g kg-1 ) were associated with lower YRP and AEP . By contrast, soil available P < 25.0 mg kg-1 resulted in decreased YRP (15.3 to 11.4%) and AEP (32.3 kg kg-1 to 26.2 kg kg-1 ), whereas soil available P > 25.0 mg kg-1 maintained the relatively stable YRP and AEP . Also, the YRP and AEP were significantly higher for single-cropping rice compared to other cropping systems. Moreover, the rice genotypes such as 'Longdun', 'Kendao' and 'Jigeng' had higher YRP and AEP than the average value. Overall, the fertilizer-P rate was the primary factor affecting YRP and AEP , and the recommended P fertilizer rate can be reduced by 9-21 kg P ha-1 compared to existing expert recommendations. CONCLUSION: The present study highlights the role of fertilizer-P rate in maximizing the YRP and AEP , thereby providing a strong basis for future fertilizer management in rice cultivation systems. © 2023 Society of Chemical Industry.

High-Sensitivity Pressure Sensors Based on a Low Elastic Modulus Adhesive.

With the rapid development of intelligent applications, the demand for high-sensitivity pressure sensor is increasing. However, the simple and efficient preparation of an industrial high-sensitivity sensor is still a challenge. In this study, adhesives with different elastic moduli are used to bond pressure-sensitive elements of double-sided sensitive grids to prepare a highly sensitive and fatigue-resistant pressure sensor. It was observed that the low elastic modulus adhesive effectively produced tensile and compressive strains on both sides of the sensitive grids to induce greater strain transfer efficiency in the pressure sensor, thus improving its sensitivity. The sensitivity of the sensor was simulated by finite element analysis to verify that the low elastic modulus adhesive could enhance the sensitivity of the sensor up to 12%. The preparation of high-precision and fatigue-resistant pressure sensors based on low elastic modulus, double-sided sensitive grids makes their application more flexible and convenient, which is urgently needed in the miniaturization and integration electronics field.

Sunlight-Driven Continuous Flapping-Wing Motion.

Light-driven actuators that directly convert light into mechanical work have attracted significant attention due to their wireless advantage and ability to be easily controlled. However, a fundamental impediment to their application is that the continuous motion of light-driven flexible actuators usually requires a periodically switching light source or the coordination of other additional hardware. Here, for the first time, continuous flapping-wing motion under sunlight is realized through the utilization of a simple nanocrystalline metal polymer bilayer structure without the coordination of additional hardware. The light-driven performance can be controlled by adjusting the grain size of the upper nanocrystalline metallic layer or selecting metals with different thermodynamic parameters. The achieved highest frequency of flapping-wing motion is 4.49 Hz, which exceeds the frequency of real butterfly wings, thus informing the further development of sunlight-driven bionic flying animal robotics without external energy consumption. The flapping-wing motion has been used to realize a light-driven whirligig, a light-driven sailboat, and photoelectric energy harvesting. Furthermore, the flexible bilayer actuator features the ability to be driven by light and electricity, low-power actuation, a large deflection, fast actuation speed, long-time stability, strong design ability, and large-area facile fabrication. The bilayer film considered herein represents a simple, general, and effective strategy for preparing photoelectric-driven flexible actuators with target performances and informs the standardization and industrial application of flexible actuators in the future.

An ultra-large deformation bidirectional actuator based on a carbon nanotube/PDMS composite and a chitosan film.

Actuating materials can convert external stimuli (humidity, light, electricity, etc.) into mechanical energy and realize multiple forms of movements. However, a majority of current actuating materials are driven by a single stimulus with a small degree of actuation and rough control which is unfavorable for practical applications. Here, a new type of bidirectional actuating material based on carbon nanotube/PDMS composites and chitosan films is proposed. Thanks to the robust mechanical support by PDMS, due to the ultra-large water capacity in between chitosan chains and strong near-infrared light absorption by carbon nanotube layers, the actuator can be driven by humidity and light for an ultra-large actuation curvature (3.91 cm-1 in humidity actuation, 3.84 cm-1 in light actuation). The well-established light power-curvature, relative humidity-curvature profiles and a fine mechanic modelling of the actuator show the possibility of controlling the actuator's bending. A lab application as a cargo-moving device preliminarily demonstrates a robust mechanical functionality of this actuator with a low body weight.

Separation and identification of cis and trans isomers of 2-butene-1,4-diol and lafutidine by HPLC and LC-MS.

The cis and trans isomers separation of 2-butene-1,4-diol and lafutidine were studied by HPLC on two kinds of chiral columns: (S,S)-Whelk-O 1 and ChiraSpher. The isomers of 2-butene-1,4-diol can be separated on both chiral columns while the isomers of lafutidine can only be resolved on ChiraSpher column. The influence of different type and amount of mobile phase modifier on the isomers separation was extensively studied. The resolution of cis and trans isomers of 2-butene-1,4-diol was 2.61 on (S,S)-Whelk-O 1 column with hexane-ethanol (97:3, v/v) as the mobile phase. The resolution of lafutidine was 1.89 on ChiraSpher column with hexane-ethanol-THF-diethylamine (92:3:5:0.1, v/v/v/v) as the mobile phase. LC-MS methods were developed to identify the isomer peaks.

[Research progress on quantification of electroacupuncture parameters].

By reviewing literature, summarization and generalization are respectively pertormed according to different electroacupunture (EA) parameters. Based on the understanding of clinical and experimental usage of EA parameters, effects of different parameters are summarized, and a preliminary evaluation is done to point out the advantages and disadvantages. It is found out that different EA parameters would produce different effects on the body, and researches are more in the field of experimental area and less in the clinical area. What's more, the majority of scholars focuses their attention on single-factor study, leading to fewer researches on the effects of parameters combination.

[Research and thinking on needling sensation of acupoint Huantiao (GB 30)].

Taken Huantiao (GB 30) as breakthrough point, acupuncture manipulations of generating various needling sensations by different physicians are sorted. Types of acupoint needling sensations and conducting directions after acupuncture and all kinds of factors that affect needling sensations are analyzed from new perspectives. It is considered that attention should be paid to acupoint location, postures of patients, manipulation methods, types of needling sensations, transmission lines and duration time of needling sensations, etc.

[Development of Researches on the Underlying Mechanism of Acupuncture Stimulation of Baliao-points for Improving Outlet Obstruction Constipation].

Outlet obstruction constipation (OOC) is a common clinical problem affecting many people's daily life quality nowadays. Acupuncture therapy is effective in easing OOC to reduce patients' sufferings by stimulation of Baliao-points i. e., bilateral Shangliao (BL 31), Ciliao (BL 32), Zhongliao (BL 33) and Xialiao (BL 34), which has been confirmed repeatedly in clinical practice. In the present paper, the authors reviewed development of studies on the underlying mechanisms of acupuncture stimulation of Baliao-points for OOC from: 1) lowering the sensitivity of intraganglionic laminar nerve endings (rIGLEs) to rectal mechanical distension during defecation, 2) raising the level of circulating cholecystokinin (CCK) to improve the sensory threshold of the rectum, 3) lowering the excitability of γ-motor neurons in the spinal anterior horns controlling the slow contraction of the rectal sphincter muscle, 4) inhibiting the excitability of sympathetic output from the spinal lateral horns, 5) easing the tonic contraction of the pelvic muscles to reduce the release of 5-hydroxy tryptamine (5-HT), histamine, and other related chemical mediators due to local ischemia. Moreover, further study on the mechanism of acupuncture stimulation of Baliao-points underlying improving OOC may help up find more specific and effective therapeutic targets and provide more reliable experimental foundation and theoretical basis.

[Thinking on current treatment situation of acupuncture foe functional defecation disorders].

In order to optimize acupuncture treatment protocol for functional defecation disorders, literature during past 20 years is reviewed, and factors which influences acupuncture therapeutic effect are analyzed from aspects of acupoint, acupuncture technique, etc. As for the selection of acupoint, more attention should be paid on the use of Baliao, especially Zhongliao (BL 33) and Xialiao (BL 34); when Baliao is deeply needled, it is essential to acquire scientific technique. The relationship between acupuncture parameter (including electroacupuncture waveform and frequency), acupuncture techniques (including reinforcing and reducing technique, quantity of stimulation, etc. ) and acupuncture efficacy is complicated, and the scientific values of present research conclusion are in need, of further improvement. The diagnosis and treatment awareness on types of functional defecation should be strengthened, and the mental health of the constipation patients should be concerned. The combination of acupuncture and biofeedback training can have a synergistic effect, which is benefit to achieve a better long-term effect. Based on this, acupuncture treatment protocol for functional defecation disorders can be optimized to further improve the efficacy.

The Effectiveness of Electroacupuncture for Functional Constipation: A Randomized, Controlled, Clinical Trial.

Background. Electroacupuncture (EA) has been reported to treat functional constipation (FC). The aim of this study was to investigate the efficacy and safety of EA with different needle insertion method for FC. Methods. Sixty-seven participants were randomly assigned to control (EA with shallow puncture) and EA (with deep puncture) groups. Every patient received 5 treatments per week in the first two weeks, then 3 treatments per week during the following six weeks. Complete spontaneous bowel movements (CSBM), spontaneous bowel movements (SBM), Bristol stool scores (BSS), and Patient Assessment of Constipation Quality of Life (PAC-QOL) were assessed. Results. Both shallow and deep EA significantly increased CSBM frequency compared to the baseline. CSBM was increased from 0.50 ± 0.59/wk to 2.00 ± 1.67/wk with deep EA and from 0.48 ± 0.59/wk to 1.33 ± 1.09/wk with shallow EA (P < 0.05, resp.). Similar finding was noted in SBM. Deep EA was more potent than shallow EA (P < 0.05) during the treatment period. No difference was found on BSS and PAC-QOL between two groups. Conclusion. It is effective and safe with EA to treat FC. Studies with large sample size and long-term observation are needed for further investigation.

Design of a viscose based solid amine fiber: effect of its chemical structure on adsorption properties for carbon dioxide.

A solid amine fiber VF-AM-TETA was designed with viscose (VF) substrate for efficient CO2 capture, where its hydroxyl groups could serve synergizing effect in CO2-amine reaction. When grafting modification and subsequent amination were applied to VF, effect of structures of grafting monomers as well as amines on its CO2 adsorption properties was taken into account. Amines with different 1° and 2° amine ratios were investigated as amination agents in terms of amine efficiency, so as to afford the fibrous adsorbent with maximum effective reactive amine sites for CO2 capturing. Results suggested that higher content in primary amine can facilitate CO2 adsorption onto the fiber by stronger basicity and smaller steric hindrance. Consequently, optimal chemical structure provided VF-AM-TETA with satisfactory adsorption capacity of 4.08 mmol/g when amine content was 8.74 mmol/g. Constant adsorption behavior within 6 adsorption-desorption cycles indicated its desirable regeneration performance in practical use due to excellent mechanical properties of VF-AM-TETA.

Surface molecular imprinting on polypropylene fibers for rhodamine B selective adsorption.

A surface molecular imprinted fiber (MIF-B) for rhodamine B (RhB) was prepared by bonding polyethylenimine (PEI) onto polypropylene (PP) fibers and subsequently cross-linking with epichlorohydrin (ECH) in the presence of RhB. The chemical structures of composites in each synthetic step were traced by FTIR analyses. The MIF-B exhibited excellent static and dynamic adsorption properties for RhB. Its adsorption isotherm for RhB followed Langmuir model. The competitive adsorption results indicated that the MIF-B had much higher selectivity for RhB over a structural analog (rhodamine 6G) with a selectivity coefficient (K(c)) of 74.1. The MIF-B proved to be a pH-sensitive material. Poly(acrylic acid) (PAA) and PEI chains grafted on PP would stretch or shrink in response to pH, resulting in the change in size and shape of binding sites of the MIF-B. Basic condition could induce the lightly cross-linked MIF-B to swell and expand its surface area, thus providing more memory cavities and internal binding sites constructed by imprinting process and ultimately leading to higher binding capacity and better RhB recognition.

Effect of the mobile phase on the retention behavior of optical isomers of the mandelic acid derivative methyl 2-phenyl-2-(tetrahydropyranyloxy) acetate by chiral HPLC.

Conditions for separation of enantiomers of a mandelic acid derivative, methyl 2-phenyl-2-(tetrahydropyranyloxy) acetate (the analyte) were studied. Because of the presence of two chiral carbons, the analyte consists of four stereoisomers stable at ambient temperature. Chiral HPLC of the analyte resulted in four peaks, using an (S,S)-Whelk-O1 column with the mobile phase consisting of hexane and the t-butyl methyl ether (TBME). It was found that TBME dramatically changed the retention of the isomers, though it produced the best enantioseparation on (S,S)-Whelk-O1. The amount of TBME in the mobile phase influenced the degree of retention shift; 5% (v/v) TBME gave a bigger shift than 8% (v/v) and 10% (v/v). 2-Propanol did not produce the same results. The chiral separation was also tried on cellulose tris (3, 5-dimethyl phenylcarbamate) (CDMPC), but only three peaks were seen, indicating some but not full enantiomer resolution.

Comparative enantioseparation of seven triazole fungicides on (S,S)-Whelk O1 and four different cellulose derivative columns.

The comparative enantioseparation of seven chiral triazole fungicides on a Pirkle type (S,S)-Whelk O1 chiral column and four different cellulose derivative columns, namely cellulose tribenzoate (CTB), cellulose tris(4-methylbenzoate) (CTMB), cellulose triphenylcarbamate (CTPC), and cellulose tris(3,5-dimethylphenyl carbamate) (CDMPC), in normal phase mode is described. The seven triazole fungicides investigated were tebuconazole, hexaconazole, myclobutanil, diniconazole, uniconazole, paclobutrazol, and triadimenol. The chiral separation of each solute was investigated with ethanol, n-propanol, iso-propanol, and n-butanol, respectively, as polar modifier in the hexane mobile phase. The results revealed that (S,S)-Whelk O1 was less than universal and only hexaconazole and triadimenol underwent enantioseparation. Among the self-prepared cellulose derivative columns used, the enantiomeric resolution capacities for the studied analytes generally decreased in the order CDMPC > CTPC > CTMB > CTB. The best enantioseparation of the analytes was mostly obtained on CDMPC and none of them were enantioseparated on CTB. The chiral recognition mechanisms between the analytes and the chiral selectors are discussed.

The study of enantioseparation of zolmitriptan on vancomycin-bonded chiral stationary phase.

In this study, the chiral stationary phase was prepared by bonding vancomycin to 5 microm spherical silica gel according to "one-pot" synthetic strategies, and used to separate the enantiomers of zolmitriptan under polar ionic mode. The influences of mobile phase composition, such as the concentration and ratio of glacial acetic acid (HOAc) and triethylamine (TEA), on the enantioseparation were investigated, and the chiral recognition mechanism is discussed. It was found experimentally that the retention factors were increased with the increase of the HOAc/TEA concentration in a certain extent, and the ionic interactions, hydrogen bondings, and steric interactions may play key role together. The method is suitable for baseline separation of zolmitriptan enantiomers.