Microstructure and Wear Resistance of Si-TC4 Composite Coatings by High-Speed Wire-Powder Laser Cladding.

The hardness and wear resistance of the surface of TC4 titanium alloy, which is widely used in aerospace and other fields, need to be improved urgently. Considering the economy, environmental friendliness, and high efficiency, Si-reinforced Ti-based composite coatings were deposited on the TC4 surface by the high-speed wire-powder laser cladding method, which combines the paraxial feeding of TC4 wires with the coaxial feeding of Si powders. The microstructures and wear resistance of the coatings were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), Vickers hardness tester, and friction and wear tester. The results indicate that the primary composition of the coating consisted of α-Ti and Ti5Si3. The microstructure of the coating underwent a notable transformation process from dendritic to petal, bar, and block shapes as the powder feeding speed increased. The hardness of the composite coatings increased with the increasing Si powder feeding rate, and the average hardness of the composite coating was 909HV0.2 when the feeding rate reached 13.53 g/min. The enhancement of the microhardness of the coatings can be attributed primarily to the reinforcing effect of the second phase generated by Ti5Si3 in various forms within the coatings. As the powder feeding speed increased, the wear resistance initially improved before deteriorating. The optimal wear resistance of the coating was achieved at a powder feeding rate of 6.88 g/min (wear loss of 2.55 mg and friction coefficient of 0.12). The main wear mechanism for coatings was abrasive wear.

Effect of Continuous Positive Airway Pressure on Blood Pressure in Patients with Resistant Hypertension and Obstructive Sleep Apnea: An Updated Meta-analysis.

PURPOSE OF REVIEW: The effect of continuous positive airway pressure (CPAP) on resistant hypertension in patients at high risk with obstructive sleep apnea (OSA) needs further investigation. We aimed to determine the effect of CPAP on blood pressure in patients with resistant hypertension and OSA. Databases including PubMed, EMBASE, MEDLINE, the Cochrane Library, and CMB were searched. Data were pooled using a random-effects or fixed-effects model to derive weighted mean differences (WMDs) and 95% confidence intervals (CIs). RECENT FINDINGS: A total of 12 trials and 718 participants were included. Compared with control, CPAP significantly reduced 24-h systolic blood pressure (SBP) (WMD: - 5.92 mmHg [ - 8.72, - 3.11]; P＜0.001), 24-h diastolic blood pressure (DBP) (WMD: - 4.44 mmHg [- 6.26 , - 2.62]; P ＜0.001),  daytime SBP (WMD: - 5.76 mmHg [ - 9.16, - 2.36]; P ＜0.001),  daytime DBP (WMD: - 3.92 mmHg [- 5.55, - 2.30];  nighttime SBP (WMD: - 4.87 mmHg [ - 7.96 , - 1.78]; P = 0.002), and nighttime DBP (WMD: - 2.05 mmHg [- 2.99, - 1.11]; P＜0.001) in patients with resistant hypertension and OSA. CPAP improved the blood pressure both in the short (＜3 months) and long term (≥ 3 months). No significant impact on mean heart rate was noted (WMD: -2.76 beats per min [- 7.50, 1.97]; P = 0.25). CPAP treatment was associated with BP reduction in patients with resistant hypertension and OSA.

Synthesis of N-Difluoromethyl Carbonyl Compounds from N-Difluoromethylcarbamoyl Fluorides.

Fluorinated small molecules are commonly used in functional small-molecule chemistry, and N-difluoromethyl (N-CF2H) compounds are particularly intriguing due to their unique and unexplored physiochemical properties. However, despite limited progress, a general methodological approach to the synthesis of N-CF2H compounds remains elusive. Here, guided by computation, we present a simple and practical protocol to access N-CF2H amides and related carbonyl derivatives. The protocol involves a one-pot conversion of thioformamides through desulfurization-fluorination and acylation, providing N-difluoromethylcarbamoyl fluoride building blocks that can be further diversified to a variety of unexplored N-CF2H carbonyl compounds with rich functionality. Additionally, preliminary studies on their properties and stability showcased their potential application in pharmaceuticals and agrochemicals.

Exosomal miR-3174 induced by hypoxia promotes angiogenesis and metastasis of hepatocellular carcinoma by inhibiting HIPK3.

Hepatocellular carcinoma (HCC) is a highly malignant tumor with rich blood supply. HCC-derived exosomes containing hereditary substances including microRNAs (miRNAs) were involved in regulating tumor angiogenesis and metastasis. Subsequently, series experiments were performed to evaluate the effect of exosomal miR-3174 on HCC angiogenesis and metastasis. HCC-derived exosomal miR-3174 was ingested by human umbilical vein endothelial cells (HUVECs) in which HIPK3 was targeted and silenced, causing subsequent inhibition of Fas and p53 signaling pathways. Furthermore, exosomal miR-3174 induced permeability and angiogenesis of HUVECs to enhance HCC progression and metastasis. Under hypoxia, upregulated HIF-1α further promoted the transcription of miR-3174. Moreover, HNRNPA1 augmented the package of miR-3174 into exosomes. Clinical data analysis confirmed that HCC patients with high-level miR-3174 were correlated with worse prognosis. Thus, exosomal miR-3174 induced by hypoxia promotes angiogenesis and metastasis of HCC by inhibiting HIPK3/p53 and HIPK3/Fas signaling pathways. Our findings might provide potential targets for anti-tumor therapy.

Influence of transitional care on the clinical manifestations among patients with COVID­19: A single­center, double­blinded, randomized survey.

Pneumonia and acute respiratory distress syndrome are the major complications of coronavirus disease 2019 (COVID-19). Transitional care is indispensable in successfully transitioning patients with COVID-19 from hospital to home and preventing adverse events of this disease. The purpose of the present study was to analyze the effects of transitional care on improvements in inflammation and pulmonary function in patients with COVID-19. Data of all hospitalized patients with COVID-19 (n=242) discharged from Mudanjiang Medical University (Mudanjiang, China) between May 2020 and October 2020 were retrospectively collected. Patients with COVID-19 had been hospitalized and assigned to receive transitional care (n=126) or usual care (n=116) and were followed up for 12 months. Hospital stay, inflammation and pulmonary function were compared in patients with COVID-19 between the transitional care and usual care group. Transitional care significantly improved physical symptoms, anxiety, depression and empathy of the patients for other patients affected. Compared to the usual care group, marked improvements in typical symptoms, including dyspnea, asthenia, cough, nausea, chest pain, myalgia, headache, fever, diarrhea, chest pain, dizziness, conjunctivitis, as well as disorders of smell and taste, were observed in the transitional care group. Patients in the transitional care group had a shorter hospital stay than those patients in the usual care group. Furthermore, transitional care decreased inflammation and ameliorated pulmonary function in patients with COVID-19. In conclusion, transitional care has an essential role in the improvement of physical symptoms, inflammation and pulmonary function in patients with COVID-19 [Chinese Clinical Trial Registry (ChiCTR) registration no. ChiCTR2200060295; 26.05.2022].

Retrospective analysis of hepatic perivascular epithelioid cell tumour (PEComa) in a single centre for clinical diagnosis and treatment clinical diagnosis and treatment of hepatic PEComa.

ABSTRACT: Our primary objective was to investigate the clinical features, diagnosis, treatment and prognosis of hepatic perivascular epithelioid cell tumour (PEComa).Thirty-five cases of pathologically proven hepatic PEComa that were treated in the Department of Hepatobiliary Centre of the First Affiliated Hospital of Nanjing Medical University from January 2008 to February 2019 were retrospectively analysed, and the literature was also reviewed.Twenty-nine females and 6 males were included in this study. The mean age of these patients was 48.0 years (range, 21-75 years). Thirteen patients complained of upper abdominal pain or discomfort, while others were accidentally discovered by imaging examination. Hepatic PEComas tended to occur in the right lobe of the liver (20 cases in the right lobe, 13 in the left lobe and 2 in the caudate lobe). Two cases were characterized by multiple tumours, and the remaining cases were single lesions (range, 1.2-12 cm). Only 8 cases were correctly diagnosed by the preoperative imaging examination, and the correct diagnosis rate was only 22.9%. The postoperative immunohistochemistry analysis showed that hepatic PEComas are positive for human melanoma black 45, Melan-A and smooth muscle actin, with the exception of 1 case that was negative for Melan-A. All patients undergoing an operation accepted regular follow-up, and the average time was 66.5 months (range, 3-132 months). Two patients who experienced tumour recurrence and 1 patient who died of cardiovascular disease, but the remaining patients showed no evidence of tumour recurrence or metastasis during the follow-up period.Hepatic PEComas are a rare type of tumours that mainly occur in young and middle-aged women. The lack of clinical manifestations and imaging findings increases the difficulty of determining a preoperative diagnosis, which mainly depends on the results of pathological examinations. Surgery is currently the only effective treatment, and long-term clinical follow-up is necessary due to the aggressive behaviour and relapse of hepatic PEComa in some patients.

Event-based fuzzy resilient control of nonlinear DC Microgrids under denial-of-service attacks.

This paper focuses on designing an event-triggered fuzzy resilient controller for networked nonlinear DC microgrid (MG) with constant power loads (CPLs) in the presence of denial-of-service (DoS) attacks. First, an attack-resilient event-triggered communication scheme is introduced to reduce the communication overhead of the DC MG while achieving the desired performance despite the presence of the DoS attacks. Second, the nonlinear event-triggered DC MG system with CPLs is modeled as a T-S fuzzy system with artificial delay through the sector nonlinearity approach combined with time-delay system modeling method. Then, by employing the noncontinuous piecewise Lyapunov-Krasovskii functional (NPLKF) approach, the asymptotic stability criterion of the built event-triggered T-S fuzzy DC MG is obtained in the form of linear matrix inequalities (LMIs), and a design method of fuzzy controller is proposed. Finally, case studies are presented to validate the efficiency of our proposed method.

ASPM combined with KIF11 promotes the malignant progression of hepatocellular carcinoma via the Wnt/ß-catenin signaling pathway.

To investigate the molecular mechanism of assembly factor for spindle microtubules (ASPM) in the regulation of the malignant progression of hepatocellular carcinoma (HCC), bioinformatics analysis was utilized to analyze the role of ASPM in the malignant progression of HCC and its potential interaction with the kinesin family member 11 (KIF11) gene. The expression levels of ASPM and KIF11 were detected by reverse transcription-quantitative PCR and western blotting. Following knockdown of ASPM expression, Cell Counting Kit-8/colony formation assays were performed to detect cell viability and proliferation. Wound healing and Transwell assays were employed to detect cell migration and invasion. Additionally, a co-immunoprecipitation (CO-IP) assay was used to detect whether there was an interaction between ASPM and KIF11. KIF11 overexpression was performed to verify if ASPM exerted its effects via KIF11. ASPM was highly expressed in HCC tissues and cells, and was closely associated with a poor prognosis of patients with HCC. Interference with ASPM expression markedly inhibited the viability, proliferation, invasion and migration of HCC cells. Using a CO-IP assay, it was revealed that there was an interaction between ASPM and KIF11. Rescue experiments subsequently revealed the regulatory effects of ASPM on the activity, proliferation, invasion and migration of HCC cells via KIF11. Finally, western blot analysis demonstrated that ASPM in combination with KIF11 promoted the malignant progression of HCC by regulating the activity of the Wnt/ß-catenin signaling pathway. Therefore, the present study demonstrated that ASPM may interact with KIF11 in HCC cells to promote the malignant progression of HCC via the Wnt/ß-catenin signaling pathway.

Clinical efficacy of anesthesia with intensive care nursing in attenuating postoperative complications in patients with breast cancer.

OBJECTIVE: Complications frequently occur in patients with breast cancer after surgery. Anesthesia nursing plays an important role in decreasing complications for such patients. Thus, this study investigated the effects of anesthesia with intensive care nursing (AICN) on complication rates in patients with breast cancer after surgery. METHODS: Eighty-two patients with breast cancer were recruited in this study. Complications were compared between the anesthesia with usual nursing care (AUCN) and AICN groups. RESULTS: The results demonstrated that AICN decreased the rates of incision infection, drug extravasation, and catheter exposure, as well as pain and inflammation scores, compared with the findings in the AUCN group. AICN improved the time to orientation and decreased the incidence of nausea, anxiety, depression, and vomiting versus AUCN. In addition, AICN shortened the time to awakening after anesthesia compared with the effects of AUCN. Furthermore, AICN shortened hospital stay and increased survival rates. Notably, AICN improved health-related quality of life as measured using the EORTC QLQ-C30 questionnaire. CONCLUSION: AICN provided more benefits and better postoperative outcomes than AUCN, suggesting its utility for minimizing complications in patients with breast cancer after surgery.

Conjugation of staphylokinase with the arabinogalactan-PEG conjugate: Study on the immunogenicity, in vitro bioactivity and pharmacokinetics.

Staphylokinase (SAK) is a bacterial protein with profibrinolytic activity. However, SAK suffers from short serum half-life and high immunogenicity. PEGylation with high Mw (20 kDa or 40 kDa) could decrease the immunogenicity and prolong the serum half-life of the proteins. However, the PEGylated protein could induce the anti-PEG antibodies and its bioactivity was significantly decreased. Arabinogalactan (AG) is a health-promoting substance with numerous biological activities. Conjugation of AG is an alternative strategy to solve the above-mentioned problems. However, conjugation with AG significantly decreased the bioactivity of a protein by shielding the bioactive domain. Here, AG conjugation and PEGylation were combined to improve the therapeutic efficacy of SAK. PEG with low Mw (2 kDa or 5 kDa) acted as a linker to conjugate AG from Larix. As compared with SAK-AG (22.3%), the conjugates (SAK-P2K-AG and SAK-P5K-AG) largely maintained the bioactivity of SAK (73.8% and 62.9%). The two conjugates both showed an 8-fold decrease in the SAK-specific IgG titers and a prolonged serum half-life. Moreover, the conjugates did not render any apparent toxicity to the heart, liver and renal functions of mice. Thus, our conjugation strategy is promising for the development of an effective long-acting therapeutic protein.

The phenyl linker markedly increases the immunogenicity of the pneumococcal polysaccharide conjugate vaccine.

OBJECTIVE: Capsular polysaccharide (PS) of Streptococcus pneumoniae is a key virulence factor and typically conjugated with a carrier protein. It is necessary to improve the immunogenicity of the conjugate vaccine against S. pneumoniae. RESULTS: A phenyl linker between tetanus toxoid (TT) and S. pneumoniae Type 14 PS was used to improve the PS-specific immunogenicity of the conjugate vaccine. As compared with the one with the amyl linker (PS-TT), the conjugate with the phenyl linker (PS-phe-TT) decreased the TT-specific IgG titers and significantly increased the PS-specific IgG titers and the IL-5 level. CONCLUSION: The phenyl linker could potentiate a robust humoral immune response to PS by decreasing the carrier-induced epitopic suppression effect. PS-phe-TT was expected to act as an effective vaccine against S. pneumoniae.

Conjugation with Eight-Arm PEG Markedly Improves the In Vitro Activity and Prolongs the Blood Circulation of Staphylokinase.

Staphylokinase (SAK) is a profibrinolytic protein and can be used for therapy of acute myocardial infarction and coronary thrombosis. However, SAK suffers from a short serum half-life time (∼6 min) that limits its clinical application. PEGylation prolongs the half-life time of SAK, whereas it significantly decreases the bioactivity of SAK for the steric shielding effect of PEG. To improve the bioactivity and prolong the half-life time of SAK, 8-arm PEG maleimide (8-arm PEG) was used for conjugation of multiple SAK molecules in one entity. C terminus of SAK was engineered with cysteine residue, followed by reaction with the maleimide moieties of 8-arm PEG to obtain the conjugate (SAKp-PEG). Conjugation with 8-arm PEG retained the secondary structure of SAK, slightly perturbed the tertiary structure of SAK, and essentially maintained its in vitro bioactivity by the multivalence of SAK. Conjugation with 8-arm PEG increased the hydrodynamic volume and thus significantly prolonged the half-life time of SAK. SAKp-PEG elicited a 1.4-fold increase in the SAK-specific IgG titers as compared with SAK, and rendered no apparent toxicity to the cardiac, liver and renal functions of mice. Thus, multiple conjugation of a protein with 8-arm PEG was an effective strategy to develop a long-acting protein drug with improved bioactivity and prolonged blood circulation.

Conjugation of the CRM197-inulin conjugate significantly increases the immunogenicity of Mycobacterium tuberculosis CFP10-TB10.4 fusion protein.

Mycobacterium tuberculosis (Mtb) is a serious fatal pathogen that causes tuberculosis (TB). Effective vaccination is urgently needed to deal with the serious threat from TB. Mtb-secreted protein antigens are important virulence determinants of Mtb with poor immunogenicity. Adjuvants and antigen delivery systems are thus highly desired to improve the immunogenicity of protein antigens. Inulin is a biocompatible polysaccharide (PS) adjuvant that can stimulate a strong cellular and humoral immunity. Bacterial capsular PS and haptens have been conjugated with cross-reacting material 197 (CRM197) to improve their immunogenicity. CFP10 and TB10.4 were two Mtb-secreted immunodominant protein antigens. A CFP10-TB10.4 fusion protein (CT) was used as the antigen for covalent conjugation with the CRM197-inulin conjugate (CRM-inu). The resultant conjugate (CT-CRM-inu) elicited high CT-specific IgG titers, stimulated splenocyte proliferation and provoked the secretion of Th1-type and Th2-type cytokines. Conjugation with CRM-inu significantly prolonged the systemic circulation of CT and exposure to the immune system. Moreover, CT-CRM-inu showed no apparent toxicity to cardiac, hepatic and renal functions. Thus, conjugation of CT with CRM-inu provided an effective strategy for development of protein-based vaccines against Mtb infection.

Efficacy and safety of remifentanil for analgesia in cesarean delivery.

BACKGROUND: This study aimed to assess the efficacy and safety of remifentanil as a general anesthetic during cesarean delivery. MATERIAL AND METHODS: Fifty women with singleton pregnancies undergoing cesarean delivery were randomly divided into intervention and control groups, each group containing 25 subjects. Participants in the intervention group received remifentanil (infused at 2 µg/kg/h), whereas subjects in the control group were given dexmedetomidine (infused at 0.4 µg/kg/h). Outcome measurements included mean arterial blood pressure (MAP), heart rate (HR), bispectral index (BIS), Apgar scores at 1 and 5 minutes, and the pH, PCO2, PO2, and base excess (BE) of umbilical venous and arterial blood. RESULTS: Forty-four participants completed the study. Patients in the intervention group did not experience greater effect and safety than those in the control group (P > .05), although MAP and BIS values decreased significantly immediately before laryngoscopy (P < .05). In addition, BIS values were reduced significantly at the time of skin incision, at uterine incision, and immediately after fetal delivery when compared with baseline values in both groups (P < .01). CONCLUSION: This study concluded that remifentanil and dexmedetomidine exhibited similar efficacy and safety during general anesthesia for cesarean delivery.

Optimizing the Reliability and Performance of Service Composition Applications with Fault Tolerance in Wireless Sensor Networks.

The services composition technology provides flexible methods for building service composition applications (SCAs) in wireless sensor networks (WSNs). The high reliability and high performance of SCAs help services composition technology promote the practical application of WSNs. The optimization methods for reliability and performance used for traditional software systems are mostly based on the instantiations of software components, which are inapplicable and inefficient in the ever-changing SCAs in WSNs. In this paper, we consider the SCAs with fault tolerance in WSNs. Based on a Universal Generating Function (UGF) we propose a reliability and performance model of SCAs in WSNs, which generalizes a redundancy optimization problem to a multi-state system. Based on this model, an efficient optimization algorithm for reliability and performance of SCAs in WSNs is developed based on a Genetic Algorithm (GA) to find the optimal structure of SCAs with fault-tolerance in WSNs. In order to examine the feasibility of our algorithm, we have evaluated the performance. Furthermore, the interrelationships between the reliability, performance and cost are investigated. In addition, a distinct approach to determine the most suitable parameters in the suggested algorithm is proposed.

Metabolic regulation of magnolol on the nuclear receptor, liver X receptor.

The aim of the present study was to investigate whether magnolol, the essential component of the traditional Chinese medicine, Magnolia officinalis, can pass through liver X receptor α (LXRα), to subsequently play an important role in the lipid metabolic balance. Using a HepG2 human hepatoma cell line, mammalian cellular one-hybridization and mammalian cell transcriptional activation experiments were performed to detect the combination degree of magnolol at different concentrations with LXRα, and assess the transcriptional activity. In addition, using a THP-1 human monocytic cell line, quantitative polymerase chain reaction was performed to assess the effect on the expression levels of downstream genes. Magnolol was shown to dose-dependently combine with LXRα, and subsequently regulate the transcriptional activity of LXRα. In addition, magnolol was found to adjust the expression of associated LXRα downstream genes in the macrophages. In conclusion, magnolol was demonstrated to affect LXRα, which may outline a new molecular mechanism through which magnolol exerts a lipid-lowering function.

[In vivo interleukin-10 gene transfer down-regulates myocardial matrix metalloproteinase and myocardial collagen expressions in rats with acute myocardial infarction].

OBJECTIVE: We investigated the in vivo effects of recombinant adenovirus-associated virus type-2 (AAV-2) mediated interleukin-10 (IL-10) gene transfer on the expression of matrix metalloproteinase (MMP)-2, 9, tissue inhibitor of metalloproteinase (TIMP)-1, collagen type I and type III in a rat acute myocardial infarction model. METHOD: Male Sprague-Dawley (SD) rats were randomly divided into three groups (each n = 6): sham operation group, MI/AAV2 group, and MI/AAV2-IL-10 group (10(10) vg/ml x 0.1 ml injection at peri-infarct regions immediately post MI). Five days later, the expressions of MMP-2 and MMP-9 were measured by RT-PCR, Western blot and zymography. The expression of TIMP-1 was measured by RT-PCR and Western blot. Collagen type I and type III were assessed by RT-PCR and immunohistochemical stain. RESULTS: The myocardial expressions of MMP-2, MMP-9 and collagen contents in MI/AAV2 group were significantly increased than those in sham operation group. Myocardial expressions of MMP-2, MMP-9 were significantly decreased and the expression of TIMP-1 significantly increased in the MI/AAV2-IL-10 group than those in MI/AAV2 group. Moreover, the expressions of collagen type I, collagen type III and the ratio of I/III collagen in border zones of infarcted myocardium were decreased by 47.6% (P < 0.01), 23.6% (P < 0.05), and 17.9% (P < 0.05) respectively, while the expression of TIMP-1 increased by 73.1%(P < 0.05) in MI/AAV2-IL-10 group compared to MI/AAV2 group. CONCLUSION: In vivo myocardial IL-10 transfer reduced myocardial MMP and collagen expression and increasing the TIMP expression.

Molecular cloning, expression profiling, and yeast complementation of 19 beta-tubulin cDNAs from developing cotton ovules.

Microtubules are a major structural component of the cytoskeleton and participate in cell division, intracellular transport, and cell morphogenesis. In the present study, 795 cotton tubulin expressed sequence tags were analysed and 19 beta-tubulin genes (TUB) cloned from a cotton cDNA library. Among the group, 12 cotton TUBs (GhTUBs) are reported for the first time here. Transcription profiling revealed that nine GhTUBs were highly expressed in elongating fibre cells as compared with fuzzless-lintless mutant ovules. Treating cultured wild-type cotton ovules with exogenous phytohormones showed that individual genes can be induced by different agents. Gibberellin induced expression of GhTUB1 and GhTUB3, ethylene induced expression of GhTUB5, GhTUB9, and GhTUB12, brassinosteroids induced expression of GhTUB1, GhTUB3, GhTUB9, and GhTUB12, and lignoceric acid induced expression of GhTUB1, GhTUB3, and GhTUB12. When GhTUBs were transformed into the Saccharomyces cerevisiae inviable mutant, tub2, which is deficient in beta-tubulin, one ovule-specific and eight of nine fibre-preferential GhTUBs rescued this lethality. This study suggests that the proteins encoded by cotton GhTUBs are involved during cotton fibre development.

The ascorbate peroxidase regulated by H(2)O(2) and ethylene is involved in cotton fiber cell elongation by modulating ROS homeostasis.

Ascorbate peroxidase (APX) is a reactive oxygen species (ROSs) scavenging enzyme involved in regulation of intracellular ROS levels by reduction of H(2)O(2) to water using ascorbate as an electron donor. In New Phytologist 2007; 175:462-71, we identified a cotton cytosolic APX1 (GhAPX1) that was significantly accumulated during the fast fiber-cell elongation period, through a proteomics approach. Both the transcript levels of GhAPX1 and the total APX activity were highly induced in response to in vitro applied H(2)O(2) or ethylene. Further analysis showed that ethylene promoted H(2)O(2) production 1 day after it was included in the culture medium, suggesting that H(2)O(2) induced cell elongation processes may be placed downstream of the ethylene signal transduction pathway. In this addendum, quantitative real-time RT-PCR showed that only cytosolic APX1, not other cotton APX genes including a second cytosolic APX2, a glyoxysomal and a stromal APXs, was up-regulated during fiber cell elongating. Exogenous H(2)O(2) was found to induce ethylene production if wild-type cotton ovules were cultured for a longer period of time, implying that there was a feedback regulatory mechanism from H(2)O(2) to ethylene biosynthesis in modulating cotton fiber development.

Saturated very-long-chain fatty acids promote cotton fiber and Arabidopsis cell elongation by activating ethylene biosynthesis.

Fatty acids are essential for membrane biosynthesis in all organisms and serve as signaling molecules in many animals. Here, we found that saturated very-long-chain fatty acids (VLCFAs; C20:0 to C30:0) exogenously applied in ovule culture medium significantly promoted cotton (Gossypium hirsutum) fiber cell elongation, whereas acetochlor (2-chloro-N-[ethoxymethyl]-N-[2-ethyl-6-methyl-phenyl]-acetamide; ACE), which inhibits VLCFA biosynthesis, abolished fiber growth. This inhibition was overcome by lignoceric acid (C24:0). Elongating fibers contained significantly higher amounts of VLCFAs than those of wild-type or fuzzless-lintless mutant ovules. Ethylene nullified inhibition by ACE, whereas C24:0 was inactive in the presence of the ethylene biosynthesis inhibitor (l-[2-aminoethoxyvinyl]-glycine), indicating that VLCFAs may act upstream of ethylene. C24:0 induced a rapid and significant increase in ACO (for 1-aminocyclopropane-1-carboxylic acid oxidase) transcript levels that resulted in substantial ethylene production. C24:0 also promoted Ser palmitoyltransferase expression at a later stage, resulting in increased sphingolipid biosynthesis. Application of C24:0 not only stimulated Arabidopsis thaliana root cell growth but also complemented the cut1 phenotype. Transgenic expression of Gh KCS13/CER6, encoding the cotton 3-ketoacyl-CoA synthase, in the cut1 background produced similar results. Promotion of Arabidopsis stem elongation was accompanied by increased ACO transcript levels. Thus, VLCFAs may be involved in maximizing the extensibility of cotton fibers and multiple Arabidopsis cell types, possibly by activating ethylene biosynthesis.