First Report of Sweet Potato Virus E(SPVE) Infecting Sweet Potato in China.

Sweet potato (Ipomoea batatas [L.] Lam.) is a versatile crop, cultivated in the subtropical and tropical areas, as food, fodder, and industrial raw material crop. In China, sweet potato has been used as a health-care food in recent years, as it contains a wide range of nutrients and xenobiotic phytochemicals. However, viral diseases are major constraint for the sweet potato yield and quality, especially the seed production and quality. Over 30 species of viruses infect sweet potato worldwide (Clark et al. 2012). More recently, a few new viruses infected sweet potato were identified, such as sweet potato virus E (SPVE), which was reported in Korea(Jo et al. 2020). In May 2022, a sweet potato sample (JSXZ1) with virus-like symptom, such as mosaic and vein clearing were collected from sweet potato germplasm Xuzhou resource nursery, Jiangsu Province, China (N34˚16', E117˚18') (Fig. S1A). To investigate the virus disease, the sample JSXZ1 showing the typical symptoms of disease was prepared for Small-RNA (sRNA) deep-sequencing. The sRNA library was constructed using TruSeq™ Small RNA Sample Prep Kits (Illumina, San Diego, USA) and sequenced using the Illumine Hiseq 2500 platform by LC-Bop Technologies (Hangzhou) CO., LTD. The sample was sequenced to obtain 26, 358, 439 raw reads and 22, 969, 139 clean reads after quality control trimming and analysis. The Velvet 1.0.5 software was used to de novo assemble the clean reads (18 to 28 nt) into larger contigs, which were then compared with the nucleotide sequences in the National Center for Biotechnology Information (NCBI) database using the BLASTn algorithm. Viruses found in the sample were sweet potato latent virus (SPLV), sweet potato feathery mottle virus (SPFMV), sweet potato chlorotic stunt virus (SPCSV), sweet potato badnavirus A (SPBV-A) and sweet potato badnavirus B (SPBV-B). Surprisingly, besides the viruses listed above, 28 contigs matched sequences of SPVE isolate GS (MH388502). To verify the result, total RNA was extracted from the sample JSXZ1 and from other leave samples (JSXZ2-JSXZ5) that contained SPFMV, SPVC, SPLV, SPVG respectively stored in lab using FastPure Universal Plant Total RNA Isolation Kit (Vazyme Biotech Co., LTD, Nanjing, China). cDNA was synthesized using random primer (hexadeoxyribonucleotide mixture; pd(N)6). The cDNA serves as template in PCR using a newly designed primer pairs based on SPVE p1 gene (SPVE-F: 5'- TCACCAAAAAGAATGCTACAAC-3'/SPVE-R: 5'-GAAATCCTCCCACTCTCCATA-3'). An expected ~500-bp PCR fragment was obtained in JSXZ1, while none of the fragment was obtained from JSXZ2-JSXZ5 (Fig. S1B). The PCR fragment was cloned into pMD18-T vector (Takara Bio Inc., Beijing, China) and plasmid DNA from transformed Escherichia coli DH5α cell (n=3) were commercially sequenced by Sangon Biotech (Shanghai) Co., Ltd. The sequences of the three fragment clones we obtained were 100% identical when compared. A BLASTN analysis of the sequences revealed that they are specific to SPVE and shared 98.62% nucleotide identity to SPVE GS isolate (MH388502) and one sequence was submitted to GenBank (Accession number OQ948331). To determine the occurrence of SPVE in infected sweet potato plants, a total of 37 leaves samples with viral symptom collected from Shandong Province (n=6) and Jiangsu Province (n=31) were indexed by RT-PCR as described before. Only 9 (24.3%) out of 37 from Shandong (n=1) and Jiangsu (n=8) were positive to SPVE respectively. In addition, five additional viruses (SPFMV, SPVC, SPVG, SPLV, SPCSV) were detected among these 37 samples and always in a mixed infection of two or more viruses. To our knowledge, this is the first report of SPVE infecting sweet potato in China. Sweet potato is an important crop in China and other countries (Zhang et al. 2023). China is the largest sweet potato producer all over the world. In addition, as sweet potato is produced through the vegetative propagation mode, thus, more attention should be paid to detection and monitoring of occurrence of SPVE in China.

The characteristics and the multiple functions of integrin ß1 in human cancers.

Integrins, which consist of two non-covalently linked α and ß subunits, play a crucial role in cell-cell adhesion and cell-extracellular matrix (ECM) interactions. Among them, integrin ß1 is the most common subunit and has emerged as a key mediator in cancer, influencing various aspects of cancer progression, including cell motility, adhesion, migration, proliferation, differentiation and chemotherapy resistance. However, given the complexity and sometimes contradictory characteristics, targeting integrin ß1 for therapeutics has been a challenge. The emerging understanding of the mechanisms regulating by integrin ß1 may guide the development of new strategies for anti-cancer therapy. In this review, we summarize the multiple functions of integrin ß1 and signaling pathways which underlie the involvement of integrin ß1 in several malignant cancers. Our review suggests the possibility of using integrin ß1 as a therapeutic target and highlights the need for patient stratification based on expression of different integrin receptors in future clinical studies.

First Report of Meloidogyne enterolobii Infecting Solanum nigrum in China.

Black nightshade (Solanum nigrum) typically grows as a weed species, but it is also widely used as an herb to treat stomach ulcers and dermal infections in many countries (Jabamalairaj et al. 2019). In April 2023, extensive root galls similar to those associated with by root-knot nematodes (RKNs), Meloidogyne spp., were observed on the roots of black nightshade in several commercial fields in Lufeng county (22°55'57.44″N, 115°33'10.31″E), Guangdong Province, China. Upon inspection, there were one to several female RKN in each gall, and egg masses protruding through the root surface. The disease incidence rate was more than 90% in each field using the random sampling method. The nematode population densities in the samples ranged from 279 to 656 eggs and second-stage juveniles (J2s) per gram of fresh roots. Females and egg masses were collected from the roots, and egg masses were incubated in sterile water at 25°C to obtain J2s. Males were not collected in root galling or soil samples. The J2 tail is thin with a broad, bluntly pointed tip, and a clearly defined hyaline tail terminus. Measurements of J2 (n = 20) included: L= 440 ± 30.5 (384 to 500) µm, stylet = 12.3 ± 0.7 (11.3 to 13.7) µm, tail = 51.6 ± 2.4 (47.9 to 57.0) µm. For females (n = 15), vulval slit length = 25.5 ±1.9 (23.6 to 29.1) µm, vulval slit to anus distance = 22.1 ± 3.0 (18.2 to 27.0) µm. Stylet knobs in females are divided longitudinally by a groove so that each knob appears as two. The perineal patterns are round to ovoid, with coarse and smooth striae, moderate to high dorsal arch and mostly lacking distinct lateral lines. Morphological characteristics from J2s and perineal patterns from adult females fit the original description of M. enterolobii (Yang and Eisenback 1983). Furthermore, species identity was explored by sequencing the D2-D3 region of the 28S rRNA gene using primers D2A/D3B (Vrain et al. 1992), and the mtDNA cytochrome c oxidase I (COI) genes using primers JB3/JB5 (Derycke et al. 2005). The sequences for the target genes were 759 bp (GenBank Accession No. OR046056) and 447 bp (GenBank Accession No. OR042802), respectively. The BLAST analysis suggested 98.17~99.78% similarities to other available M. enterolobii sequences in GenBank. Species identity was further confirmed with the species-specific primer pair Me-F/Me-R (Long et al. 2006). An approximately 240 bp PCR product was produced, which was previously reported only for M. enterolobii, whereas no product was obtained from control populations of M. incognita or M. javanica. The pathogenicity test was conducted in a greenhouse at 28°C using seedlings of S. nigrum maintained in pots containing 500 cm3 sterilized soil. Ten replicates were inoculated with 800 eggs and J2s of the original population of M. enterolobii, while another 10 replicates of control plants were not inoculated. After 7 weeks, the inoculated plants exhibited galling symptoms similar to plants observed in the field, and females and egg masses were obtained by dissecting galls. No galling symptoms were observed on control plants. These results confirmed the nematode's pathogenicity. To our knowledge, this is the first record of M. enterolobii parasitizing black nightshade. M. enterolobii stands out as a highly deleterious variant among the species of RKNs owing to its extensive repertoire of host plants, pathogenicity, and proficiency in thriving and multiplying even on crops possessing resistance genes (Sikandar, 2022). In addition to being a medicinal plant, S. nigrum is a widespread weed found in fields throughout China. This report also showed that S. nigrum could play an important role as a reservoir host of M. enterolobii aiding its survival, reproduction, spread, and increasing the potential damage for host crops.

IbINV Positively Regulates Resistance to Black Rot Disease Caused by Ceratocystis fimbriata in Sweet Potato.

Black rot disease, caused by Ceratocystis fimbriata Ellis & Halsted, severely affects both plant growth and post-harvest storage of sweet potatoes. Invertase (INV) enzymes play essential roles in hydrolyzing sucrose into glucose and fructose and participate in the regulation of plant defense responses. However, little is known about the functions of INV in the growth and responses to black rot disease in sweet potato. In this study, we identified and characterized an INV-like gene, named IbINV, from sweet potato. IbINV contained a pectin methylesterase-conserved domain. IbINV transcripts were most abundant in the stem and were significantly induced in response to C. fimbriata, salicylic acid, and jasmonic acid treatments. Overexpressing IbINV in sweet potato (OEV plants) led to vigorous growth and high resistance to black rot disease, while the down-regulation of IbINV by RNA interference (RiV plants) resulted in reduced plant growth and high sensitivity to black rot disease. Furthermore, OEV plants contained a decreased sucrose content and increased hexoses content, which might be responsible for the increased INV activities; not surprisingly, RiV plants showed the opposite effects. Taken together, these results indicate that IbINV positively regulates plant growth and black rot disease resistance in sweet potato, mainly by modulating sugar metabolism.

Development of a dual RT-RPA detection for Sweet potato feathery mottle virus and Sweet potato chlorotic stuntvirus.

The disease co-infected by Sweet potato feathery mottle virus (SPFMV) and Sweet potato chlorotic stunt virus (SPCSV) is devastating in sweet potato, as it would give rise to the serious losses in both production and quality. Consequently, it is conducive for preventing and controlling this disease to detect these two viruses accurately and timely. Here we developed and optimized a dual reverse transcription recombinase polymerase amplification (RT-RPA) for rapid and accurate detection of SPFMV and SPCSV. Four special primers were designed based on the conserved sequences of SPFMV and SPCSV, respectively. The sensitivity of dual RT-RPA for SPFMV and SPCSV was 10-4 ng/µL at the optimal conditions in which the primer ratio between SPFMV and SPCSV was 2:1, and the reaction incubated for 25 min at a temperature of 39 °C. Both 61 sweet potato samples and 5 morning glory samples collected from China were tested using the dual RT-RPA successfully. Therefore, the dual RT-RPA is a reliable, rapid, sensitive method to detect these two viruses in sweet potato. It is the RT-RPA that was used for detection of SPFMV and SPCSV simultaneously firstly. This dual RT-RPA, as a convenient and powerful tool, will be useful to diagnose SPFMV and SPCSV.

Sidescan Only Neural Bathymetry from Large-Scale Survey.

Sidescan sonar is a small and low-cost sensor that can be mounted on most unmanned underwater vehicles (UUVs) and unmanned surface vehicles (USVs). It has the advantages of high resolution and wide coverage, which could be valuable in providing an efficient and cost-effective solution for obtaining the bathymetry when bathymetric data are unavailable. This work proposes a method of reconstructing bathymetry using only sidescan data from large-scale surveys by formulating the problem as a global optimization, where a Sinusoidal Representation Network (SIREN) is used to represent the bathymetry and the albedo and the beam profile are jointly estimated based on a Lambertian scattering model. The assessment of the proposed method is conducted by comparing the reconstructed bathymetry with the bathymetric data collected with a high-resolution multi-beam echo sounder (MBES). An error of 20 cm on the bathymetry is achieved from a large-scale survey. The proposed method proved to be an effective way to reconstruct bathymetry from sidescan sonar data when high-accuracy positioning is available. This could be of great use for applications such as surface vehicles with Global Navigation Satellite System (GNSS) to obtain high-quality bathymetry in shallow water or small autonomous underwater vehicles (AUVs) if simultaneous localization and mapping (SLAM) can be applied to correct the navigation estimate.

Biogeochemical properties and potential risk of shallow arsenic-rich sediment layers to groundwater quality in Western Bangladesh.

The arsenic-contaminated groundwater has attracted attention in much south and southeast Asian deltas, however, mainly on the deep aquifers. Here, arsenic (As) concentration and its fractionation of the sediment cores in a shallow aquifer in Bangladesh were investigated using ICP-MS, FE-EPMA, XRD and 14C-AMS chronology techniques. The results of the present study indicated that the peak concentrations of As (54.7-79.1 µg/g) were in peat layers (at a depth of 7.5-8.0 m). Several types of iron (oxyhidr)oxides and framboidal pyrite, which contain As also, were found in the peat samples. The high concentrations of As were in an exchangeable form, As-bearing iron crystalline and As-bearing organic materials. We revealed that the As-rich peat layers were formed from 3170 to 3901 cal yrs before, due to the sea level decrease in this area. The 16S rRNA gene-based phylogenetic analysis revealed that the bacterial strains in the As-rich peats were mainly affiliated with genera Acinetobacter, Enterobacter, Escherichia, Bacillus, Clostridiaceae and Acinetobacter. The geo-accumulation index (Igeo) and ecological risk index assessment were calculated for the sediments, which shows that As-rich sediment layers were in range of moderately to heavily contaminated and considerable classes, respectively. Under the permanent saturated condition, the As-rich peat layers should be considered as an important potential driver of the groundwater As in this area.

Oxytocin intensifies the mortality salience effect: Novel evidence for the social salience model of oxytocin.

Oxytocin plays an important role in human responses to threat processing. Few studies have directly examined the effects of oxytocin on our response to death-related stimuli. In the current study, 63 participants intranasally received either 32 IU of oxytocin or a placebo and thereafter completed a visual dot-probe task consisting of death-related and non-death related images. The results indicated that oxytocin enhanced participants' vigilance toward death-related images as well as increased their anxiety about and fear of death. Overall, oxytocin amplifies the defensive responses to a mortality threat, supporting the social salience model of oxytocin.

Effect of Auricular Point Acupressure on Axial Neck Pain After Anterior Cervical Discectomy and Fusion: A Randomized Controlled Trial.

Objectives: To evaluate the effect of auricular point acupressure (APA) on axial neck pain after anterior cervical discectomy and fusion (ACDF) surgery. Design: A prospective randomized controlled trial was performed. Subjects and setting: Twenty-nine participants were randomly divided into two groups, real or sham APA. Participants were enrolled from Shaoxing Hospital of Traditional Chinese Medicine, affiliated with Zhejiang Chinese Medical University. Methods: Eligible participants received a four-week real or sham APA treatment according to their assigned groups. The clinical outcomes were assessed by the criteria of Hosono et al., the Brief Pain Inventory Short Form (BPI), and the 36-item Short Form Health Survey (SF-36). In addition, plasma interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α were analyzed. Results: Patients with severe or moderate axial neck pain accounted for 28.6% and 35.7% in the real APA group at the end of treatment and one-month follow-up. BPI scores were decreased in the real APA group at the end of treatment and one-month follow-up. The total mean score of SF-36 was improved in the real APA group and significantly higher than in the sham APA group. Additional, the levels of IL-1ß, IL-6, and TNF-α were decreased in the real APA group. Conclusions: The findings supported the therapeutic effect of APA treatment on axial neck pain after ACDF surgery, and they exert the possible therapeutic effect on downregulating the levels of plasma IL-1ß, IL-6, and TNF-α.

Overexpression of Arabidopsis P3B increases heat and low temperature stress tolerance in transgenic sweetpotato.

BACKGROUND: Sweetpotato (Ipomoea batatas [L.] Lam) is suitable for growth on marginal lands due to its abiotic stress tolerance. However, severe environmental conditions including low temperature pose a serious threat to the productivity and expanded cultivation of this crop. In this study, we aimed to develop sweetpotato plants with enhanced tolerance to temperature stress. RESULTS: P3 proteins are plant-specific ribosomal P-proteins that act as both protein and RNA chaperones to increase heat and cold stress tolerance in Arabidopsis. Here, we generated transgenic sweetpotato plants expressing the Arabidopsis ribosomal P3 (AtP3B) gene under the control of the CaMV 35S promoter (referred to as OP plants). Three OP lines (OP1, OP30, and OP32) were selected based on AtP3B transcript levels. The OP plants displayed greater heat tolerance and higher photosynthesis efficiency than wild type (WT) plants. The OP plants also exhibited enhanced low temperature tolerance, with higher photosynthesis efficiency and less membrane permeability than WT plants. In addition, OP plants had lower levels of hydrogen peroxide and higher activities of antioxidant enzymes such as peroxidase and catalase than WT plants under low temperature stress. The yields of tuberous roots and aerial parts of plants did not significantly differ between OP and WT plants under field cultivation. However, the tuberous roots of OP transgenic sweetpotato showed improved storage ability under low temperature conditions. CONCLUSIONS: The OP plants developed in this study exhibited increased tolerance to temperature stress and enhanced storage ability under low temperature compared to WT plants, suggesting that they could be used to enhance sustainable agriculture on marginal lands.

Mycobacterium tuberculosis infection induces a novel type of cell death: Ferroptosis.

Ferroptosis is a lipid peroxidation-driven and iron-dependent form of programmed cell death, which is involved in a variety of physical processes and multiple diseases. Numerous reports have demonstrated that ferroptosis is closely related to the pathophysiological processes of Mycobacterium tuberculosis (M. tuberculosis) infection and is characterized by the accumulation of excess lipid peroxides on the cell membrane. In this study, the various functions of ferroptosis, and the therapeutic strategies and diagnostic biomarkers of tuberculosis, were summarized. Notably, this review provides insights into the molecular mechanisms and functions of M. tuberculosis-induced ferroptosis, suggesting potential future therapeutic and diagnostic markers for tuberculosis.

Design of an Automatically Controlled Multi-Axis Stretching Device for Mechanical Evaluations of the Anterior Eye Segment.

The young eye has an accommodative ability involving lens shape changes to focus over different distances. This function gradually decreases with age, resulting in presbyopia. Greater insights into the mechanical properties of anterior eye structures can improve understanding of the causes of presbyopia. The present study aims to develop a multi-axis stretching device for evaluating the mechanical properties of the intact eye lens. A stretching device integrating the mechanical stretcher, motor, torque sensor and data transmission mechanism was designed and developed by 3D printing. The mechanical stretcher can convert rotation into radial movement, both at constant speeds, according to the spiral of Archimedes. The loading unit equipped with eight jaws can hold the eye sample tightly. The developed device was validated with a spring of known constant and was further tested with anterior porcine eye segments. The validation experiment using the spring resulted in stiffness values close to the theoretical spring constant. Findings from measurements with porcine eye samples indicated that the measured forces are within the ranges reported in the literature. The developed multi-axis stretching device has good repeatability during experiments with similar settings and can be reliably used for mechanical evaluations of the intact eye lens.

Transcriptome Characterization and Gene Changes Induced by Fusarium solani in Sweetpotato Roots.

Sweetpotato (Ipomoea batatas) is an important root crop that is infected by Fusarium solani in both seedling and root stages, causing irregular black or brown disease spots and root rot and canker. This study aims to use RNA sequencing technology to investigate the dynamic changes in root transcriptome profiles between control check and roots at 6 h, 24 h, 3 days, and 5 days post-inoculation (hpi/dpi) with F. solani. The results showed that the defense reaction of sweetpotato could be divided into an early step (6 and 24 hpi) without symptoms and a late step to respond to F. solani infection (3 and 5 dpi). The differentially expressed genes (DEGs) in response to F. solani infection were enriched in the cellular component, biological process, and molecular function, with more DEGs in the biological process and molecular function than in the cellular component. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the main pathways were metabolic pathways, the biosynthesis of secondary metabolites, and carbon metabolism. More downregulated genes were identified than upregulated genes in the plant-pathogen interaction and transcription factors, which might be related to the degree of host resistance to F. solani. The findings of this study provide an important basis to further characterize the complex mechanisms of sweetpotato resistance against biotic stress and identify new candidate genes for increasing the resistance of sweetpotato.

Cofilin-1 as a potential biomarker for Mycobacterium tuberculosis infection.

Tuberculosis (TB) induced by Mycobacterium tuberculosis (M. tb), is one of the deadliest human infections worldwide. Our previous studies demonstrated cofilin-1 (CFL1) expression was significantly increased in exosomes from Mycobacterium avium (M. avium)-infected macrophages. The expression of CFL1 protein in M. tb infected hosts was investigated in the present study to predict whether CFL1 could have potential as a biomarker for M. tb infection. In the present study, the mRNA and protein expression levels of CFL1 in M. avium-infected macrophages and supernatants were analyzed via reverse transcription-quantitative PCR and western blotting. Furthermore, CFL1 expression in macrophages was knocked down in vivo, and then CFL1 expression levels in M. avium-infected macrophages and supernatant were detected via western blotting and ELISA. In addition, CFL1 was detected in the peripheral blood mononuclear cells and plasma of patients with TB using western blotting and ELISA. The specificity and sensitivity of CFL1 as a biomarker and the association between TB infection and normal individuals were compared and analyzed using GraphPad Prism 5. CFL1 protein expression levels were significantly increased in M. avium-infected macrophages and supernatant. Meanwhile, CFL1 was upregulated in patients with TB. Bioinformatics statistics indicated the high specificity and sensitivity of CFL1 in patients with TB. Thus, these results suggest that CFL1 may act as a potential biomarker of TB infection.

Is implicit social cognition developmentally stable? A longitudinal study.

To examine whether implicit social cognition is developmentally stable or variable, this study investigated three primary types of implicit social cognition (self-esteem, the gender-science stereotype, and racial attitude) across 2 years in a sample of Chinese adolescents and emerging adults (N = 608; 56% female; 15- to 27-year-olds). Rank-order stability analyses indicated that implicit self-esteem and implicit racial attitude manifested low stability (r = .16, .19, respectively), whereas implicit gender-science stereotype was highly stable (r = .75). Latent change score model analyses showed that: (a) the mean level of implicit self-esteem decreased across the 2 years, whereas the mean levels of implicit gender-science stereotype and implicit racial attitude manifested no changes; (b) individual changes were heterogeneous for all the three types of implicit social cognition (while some of the participants manifested increasing tendencies, 15%-46%, the others exhibited decreasing tendencies); (c) 30% of participants manifested similar changes across the three types of implicit social cognition (either increasing or decreasing over time on all three), while the remaining participants exhibited distinct changes across them. Together, these findings indicate that, developmentally, implicit social cognition is variable but also stable, though the degree of variability and stability vary across individuals and domains. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Proteomics Analysis of Exosomes From Patients With Active Tuberculosis Reveals Infection Profiles and Potential Biomarkers.

Although mycobacterial proteins in exosomes from peripheral serum of patients with tuberculosis (TB) have been identified, other exact compositions of exosomes remain unknown. In the present study, a comprehensive proteomics analysis of serum exosomes derived from patients with active TB (ATB) was performed. Exosomes from patients with ATB were characterized using nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and western blotting analysis. Then identified protein components were quantified by label-free proteomics and were determined via bioinformatics analysis. A total of 123 differential proteins were identified in ATB serum exosomes and analyzed with Gene Ontology (GO) analysis. Among these proteins heat shock protein70 (HSP70), CD81, major histocompatibility complex-I (MHC-I ) and tumor susceptibility gene101 (TSG101) were present in exosomes of ATB and normal individuals confirmed via western blotting. In addition, among identified exosomal proteins lipopolysaccharide binding protein (LBP) increased significantly, but CD36 and MHC-I decreased significantly in ATB exosomes. Meanwhile, MHC-I was down-expressed in serum and peripheral blood mononuclear cells (PBMCs) of ATB, but interestingly CD36 was down-regulated in serum and up-expressed in PBMCs of ATB patients validated with ELISA and flow cytometry. CD36 was up-regulated by M. tuberculosis H37Ra infection in macrophages and suppressed in exosomes from H37Ra infected macrophages detected by western blotting. This study provided a comprehensive description of the exosome proteome in the serum of patients with ATB and revealed certain potential biomarkers associated with TB infection.

[Study on elasticity of medical service demand at the township level in China].

OBJECTIVE: To find out the economic laws regulating medical service demand in accordance with influencing factors at the township level, thus to provide references for further adjusting the medical service demand reasonably in the future. METHODS: The model of medical service demand was established to measure the elasticity of demand in 49 township health clinics in 1995, 1999, 2003 and 2007. RESULTS: The price elasticity of outpatient and inpatient demand was stable during the four periods, and the average value was -0.029 and -0.132 respectively; the average value of income elasticity was 0.973 and 0.977, registering a downward trend in general. CONCLUSION: The medical service demand at the township level is price inelastic, indicating that it is a necessity for rural residents. The downward trend of income elasticity under the influence of some health policies illustrates a lightening in economic burden for medical service demand among rural residents in township health clinics.

IbINH positively regulates drought stress tolerance in sweetpotato.

Invertase inhibitor (INH) post-translationally regulates the activity of invertase, which hydrolyzes sucrose into glucose and fructose, and plays essential roles in plant growth and development. However, little is known about the role of INH in growth and responses to environmental challenges in sweetpotato. Here, we identified and characterized an INH-like gene (IbINH) from sweetpotato. IbINH belongs to the pectin methylesterase inhibitor super family. IbINH transcript was the most abundant in storage roots. IbINH mRNA levels were significantly up-regulated in response to drought, abscisic acid (ABA), salicyclic acid (SA) and jasmonic acid (JA) treatments. Overexpressing IbINH in sweetpotato (SI plants) led to the decrease of plant growth and the increase of drought tolerance, while down-regulation of IbINH (RI plants) by RNAi technology resulted in vigorous growth and drought sensitivity. Furthermore, sucrose was increased and hexoses was decreased in SI plants, but the opposite results were observed in RI plants. Moreover, higher levels of sugars were accumulated in SI plants in comparison to non-transgenic plants (NT plants) and RI plants during water deficit. In addition, ABA biosynthesis-involved and abiotic stress response-involved genes were prominently up-regulated in SI plants under drought stress. Taken together, these results indicate that IbINH mediates plant growth and drought stress tolerance in sweetpotato via induction of source-sink strength and ABA-regulated pathway.