Machine learning risk prediction model for bloodstream infections related to totally implantable venous access ports in patients with cancer.

Objective: This study aimed to develop and validate a machine learning-based risk prediction model for catheter-related bloodstream infection (CRBSI) following implantation of totally implantable venous access ports (TIVAPs) in patients. Methods: A retrospective cohort study design was employed, utilizing the R software package mlr3. Various algorithms including logistic regression, naive Bayes, K nearest neighbor, classification tree, and random forest were applied. Addressing class imbalance, benchmarks were used, and model performance was assessed using the area under the curve (AUC). The final model, chosen for its superior performance, was interpreted using variable importance scores. Additionally, a nomogram was developed to calculate individualized risk probabilities, enhancing clinical utility. Results: The study involved 755 patients across both development and validation cohorts, with a TIVAP-CRBSI rate of 14.17%. The random forest model demonstrated the highest discrimination ability, achieving a validated AUC of 0.94, which was consistent in the validation cohort. Conclusions: This study successfully developed a robust predictive model for TIVAP-CRBSI risk post-implantation. Implementation of this model may aid healthcare providers in making informed decisions, thereby potentially improving patient outcomes.

Wogonin induces apoptosis in macrophages by exhibiting cytotoxic and genotoxic effects.

Macrophages play an important role in defending the body against invading pathogens. In the face of pathogens, macrophages become activated and release toxic materials that disrupt the pathogens. Macrophage overactivation can lead to severe illness and inflammation. Wogonin has several therapeutic effects, including anti-inflammatory, anticancer, antioxidant, and neuroprotective effects. No studies have investigated the cytotoxic effects of wogonin at concentrations of more than 0.1 mM in RAW264.7 cells. In this study, RAW 264.7 cells were treated with wogonin, which, at concentrations of more than 0.1 mM, had cytotoxic and genotoxic effects in the RAW264.7 cells, leading to apoptosis and necrosis. Further, wogonin at concentrations of more than 0.1 mM induced caspase-3, caspase-8, and caspase-9 activation and mitochondrial dysfunction and death receptor expression. These results suggest that wogonin induces apoptosis through upstream intrinsic and extrinsic pathways by exhibiting cytotoxic and genotoxic effects.

Cyclizine induces cytotoxicity and apoptosis in macrophages through the extrinsic and intrinsic apoptotic pathways.

Cyclizine, an over-the-counter and prescription antihistamine, finds widespread application in the prevention and treatment of motion sickness, encompassing symptoms such as nausea, vomiting, dizziness, along with its effectiveness in managing vertigo. However, the overuse or misuse of cyclizine may lead to hallucinations, confusion, tachycardia, and hypertension. The molecular mechanisms underlying cyclizine-induced cytotoxicity and apoptosis remain unclear. During the 24 h incubation duration, RAW264.7 macrophages were exposed to different concentrations of cyclizine. Cytotoxicity was assessed through the lactate dehydrogenase assay. Flow cytometry employing annexin V-fluorescein isothiocyanate and propidium iodide was utilized to evaluate apoptosis and necrosis. Caspase activity and mitochondrial dysfunction were evaluated through a fluorogenic substrate assay and JC-1 dye, respectively. Flow cytometry employing fluorogenic antibodies was utilized to evaluate the release of cytochrome c and expression of death receptor, including tumor necrosis factor-α receptor and Fas receptor. Western blotting was utilized to evaluate the expression of the Bcl2 and Bad apoptotic regulatory proteins. The findings unveiled from the present study demonstrated that cyclizine exerted a concentration-dependent effect on RAW264.7 macrophages, leading to the induction of cytotoxicity, apoptosis, and necrosis. This compound further activated the intrinsic apoptotic pathway by inducing mitochondrial dysfunction, Bcl2/Bad exchange expression, cytochrome c liberation, and activation of caspases contained caspase 3, 8, and 9. Moreover, the activation of the extrinsic apoptotic pathway was observed as cyclizine induced the upregulation of death receptors and increased caspase activities. Based on our investigations, it can be inferred that cyclizine prompts cytotoxicity and apoptosis in RAW264.7 macrophages in a concentration-dependent manner by triggering both the intrinsic and extrinsic apoptotic pathways.

Gut microbiota influence frailty syndrome in older adults: mechanisms and therapeutic strategies.

Frailty syndrome denotes a decreased capacity of the body to maintain the homeostasis and stress of the internal environment, which simultaneously increases the risk of adverse health outcomes in older adults, including disability, hospitalization, falls, and death. To promote healthy aging, we should find strategies to cope with frailty. However, the pathogenesis of frailty syndrome is not yet clear. Recent studies have shown that the diversity, composition, and metabolites of gut microbiota significantly changed in older adults with frailty. In addition, several frailty symptoms were alleviated by adjusting gut microbiota with prebiotics, probiotics, and symbiosis. Therefore, we attempt to explore the pathogenesis of frailty syndrome in older people from gut microbiota and summarize the existing interventions for frailty syndrome targeting gut microbiota, with the aim of providing timely and necessary interventions and assistance for older adults with frailty.

Ethyl Lithospermate Reduces Lipopolysaccharide-Induced Inflammation through Inhibiting NF-κB and STAT3 Pathways in RAW 264.7 Cells and Zebrafish.

OBJECTIVE: To explore the anti-inflammatory effects of ethyl lithospermate in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine-derived macrophages and zebrafish, and its underlying mechanisms. METHODS: 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide (MTT) assays were performed to investigate the toxicity of ethyl lithospermate at different concentrations (12.5-100 µ mol/L) in RAW 264.7 cells. The cells were stimulated with LPS (100 ng/mL) for 12 h to establish an inflammation model in vitro, the production of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor α (TNF-α) were assessed by enzyme linked immunosorbent assay (ELISA). Western blot was used to ascertain the protein expressions of signal transducer and activator of transcription 3 (STAT3), nuclear factor kappa B (NF-κB) p65, phospho-STAT3 (p-STAT3, Tyr705), inhibitor of NF-κB (IκB) α, and phospho-I κB α (p-IκB α, Ser32), and confocal imaging was used to identify the nuclear translocation of NF-κB p65 and p-STAT3 (Tyr705). Additionally, the yolk sacs of zebrafish (3 days post fertilization) were injected with 2 nL LPS (0.5 mg/mL) to induce an inflammation model in vivo. Survival analysis, hematoxylin-eosin (HE) staining, observation of neutrophil migration, and quantitative real-time polymerase chain reaction (qRT-PCR) were used to further study the anti-inflammatory effects of ethyl lithospermate and its probable mechanisms in vivo. RESULTS: The non-toxic concentrations of ethyl lithospermate have been found to range from 12.5 to 100 µ mol/L. Ethyl lithospermate inhibited the release of IL-6 and TNF-α(P<0.05 or P<0.01), decreased IκBα degradation and phosphorylation (P<0.05) as well as the nuclear translocation of NF-κB p65 and p-STAT3 (Tyr705) in LPS-induced RAW 264.7 cells (P<0.01). Ethyl lithospermate also decreased inflammatory cells infiltration and neutrophil migration while increasing the survival rate of LPS-stimulated zebrafish (P<0.05 or P<0.01). In addition, ethyl lithospermate also inhibited the mRNA expression levels of of IL-6, TNF-α, IκBα, STAT3, and NF-κB in LPS-stimulated zebrafish (P<0.01). CONCLUSION: Ethyl lithospermate exerts anti-Inflammatory effected by inhibiting the NF-κB and STAT3 signal pathways in RAW 264.7 macrophages and zebrafish.

Risk Factors of Catheter-Related Infection in Unplanned Extubation of Totally Implantable Venous-Accessportsin Tumor Patients.

Background: Totally implantable intravenous ports (TIVAPs) are mostly used for long-term intravenous infusion therapy in cancer patients and can be left in the body for long periods of time for easy management, making them a simple and safe infusion device. Although the risks associated with long-term retention of fully implantable IV ports are less than those associated with other intravenous catheters, various complications may still occur at the time of implantation or during long-term use. Purpose: To provide a scientific basis for clinical reduction of implantable intravenous port-associated infection complications by studying the risk factors for catheter-associated infection complications in patients applying implantable intravenous ports. Methods: A retrospective study was conducted on oncology patients treated with TIVAP at our hospital between January 2017 and November 2021, with a review of patients who were unplanned for extubation. Their demographic data, underlying disease status, and surgery-related data were counted to summarize and analyze the complications and related influencing factors of implantation and postimplantation. Results: A total of 70 individuals with a mean age of 56.49 ± 12.19 years were included in the study. Among them, 39 were male and 64 had the highest percentage of epithelial tumors, followed by tumors of the lymphopoiesis system and mesenchymal tumors with 4 and 2 cases, respectively. Forty-eight of these patients did not have their ports removed as planned due to the occurrence of catheter-related hematogenous infections. In univariate analysis, BMI and neutropenia were risk factors for catheter-associated infections. In the multivariate analysis, BMI (OR = 1.38, 95% CI: 1.07-1.78, p=0.013) was an independent risk factor for catheter-associated infections. Conclusions: The overall complication rate of fully implanted intravenous ports was high, but most complications improved with symptomatic management, and no deaths due to port complications were identified. Infection was the most common complication, with catheter-associated bloodstream infection being the most common cause of unplanned port extraction. Patients with a higher BMI were at high risk of developing implantable IV port-associated infections, which may be an independent risk factor for implantable IV port-associated infections.

Circulating Neutrophil-Derived Microparticles Associated with the Prognosis of Patients with Sepsis.

INTRODUCTION: Because of its high morbidity and mortality, sepsis remains the leading cause of death in the ICU. Microparticles (MP) have been largely studied as potential diagnostic or prognostic markers in various diseases including sepsis. OBJECTIVE: The biological and clinical relevance of neutrophil-derived microparticles (NDMPs) within the MP population remains unclear. The objective of this study was to elucidate the relationship between plasma NDMPs and the prognosis of patients with sepsis and/or septic shock. METHODS: The study was designed as an observational, noninterventional clinical study. The cohort for this study included 40 sepsis and 40 septic shock patients together with 10 healthy controls admitted to the Intensive Care Unit (ICU) and the Health Surveillance Center in the Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, China, from January to November 2018, respectively. The degree of critical disease for sepsis and septic shock was evaluated, with data analyses conducted from 2018 to 2019. RESULTS: On days 1, 3 and 5 post-admission a series of data including plasma NDMP levels, patient demographics, TNF-α levels, IL-6 levels, sTREM-1 levels, and the sepsis severity score measurements were collected. A survival curve was plotted against levels of plasma NDMPs. Levels of NDMPs were observed to be higher in the septic shock patients than in the sepsis patients on days 1, 3, and 5 post-ICU admission (p < 0.05). NDMP levels were significantly increased in sepsis and septic shock patients with a parallel increase in pro-inflammatory mediators and sepsis severity score (p < 0.05) as well as mortality. CONCLUSION: Our data suggest that NDMPs may be a biomarker of sepsis severity and mortality although its implications on sepsis prognosis warrant further study.

Berberine inhibits proliferation and apoptosis of vascular smooth muscle cells induced by mechanical stretch via the PDI/ERS and MAPK pathways.

AIMS: We recently demonstrated that mechanical stretch increases the proliferation and apoptosis of vascular smooth muscle cells (VSMCs) by activating the protein disulfide isomerase (PDI) redox system, thus accelerating atherosclerotic lesion formation in the transplanted vein. At present, there are no efficient intervention measures to prevent this phenomenon. Berberine inhibits pathological vascular remodeling caused by hypertension, but the underlying mechanism is controversial. Herein, we investigate the role of berberine and the underlying mechanism of its effects on mechanical stretch-induced VSMC proliferation and apoptosis. MAIN METHODS: Mouse VSMCs cultivated on flexible membranes were pretreated for 1 h with one of the following substances: berberine, PDI inhibitor bacitracin, MAPK inhibitors, or ERS inhibitor 4-PBA. VSMCs were then subjected to mechanical stretch. Immunofluorescence and western blot were used to detect proliferation and apoptosis, as well as to analyze signaling pathways in VSMCs. KEY FINDINGS: Our results showed that berberine inhibits the PDI-endoplasmic reticulum stress system, thereby attenuating the simultaneous increase of VSMC proliferation and apoptosis in response to mechanical stretch. Interestingly, MAPK inhibitors PD98059, SP600125, and SB202190 significantly reduced the activation of ERS signaling cascades, and their combination with berberine had additive effects. The ERS inhibitor 4-PBA reduced PDI activation and ERS signaling, but not MAPK phosphorylation. Moreover, caspase-3 and caspase-12 were downregulated by berberine. SIGNIFICANCE: These results illustrate a novel mechanism of action of berberine that has practical implications. Our data provide important insights for the prevention and treatment of vascular remodeling and diseases caused by mechanical stretching during hypertension.

Critical Care Resources in Guangdong Province of China: Three Surveys from 2005 to 2015.

OBJECTIVES: Data about the critical care resources in China remain scarce. The purpose of this study was to investigate the variation and distribution of critical care resources in Guangdong province from 2005 to 2015. DESIGN: Data in regard to critical care resources were collected through questionnaires and visits every 5 years from 2005. SETTING: All hospitals in Guangdong province were screened and hospitals that provide critical care services were enrolled. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: One hundred eleven, 158, and 284 hospitals that provide critical care services were enrolled in the three consecutive surveys respectively. The number of ICUs, ICU beds, intensivists, and nurses increased to 324, 3,956, 2,470, and 7,695, respectively, by 2015. Adjusted by population, the number of ICU beds per 100,000 (100,000) population increased by 147.7% from 2005 to 2015, and the number of intensivists and nurses per 100,000 population increased by 35.3% and 55.1% from 2011 to 2015. However, the numbers in the Pearl River Delta, a richer area, were higher than those in the non-Pearl River Delta area (ICU beds: 4.64 vs 2.58; intensivists: 2.90 vs 1.61; nurses: 9.30 vs 4.71 in 2015). In terms of staff training, only 17.85% of intensivists and 14.29% of nurses have completed a formal accredited critical care training program by 2015. CONCLUSIONS: Our study was the first one to investigate the trend and distribution of critical care resources in China. The quantity of ICU beds and staff has been increasing rapidly, but professional training for staff was inadequate. The distribution of critical care resources was unbalanced. Our study can be beneficial for healthcare policymaking and the allocation of critical care resources in Guangdong province and other provinces in China.

Protein disulfide isomerase-mediated apoptosis and proliferation of vascular smooth muscle cells induced by mechanical stress and advanced glycosylation end products result in diabetic mouse vein graft atherosclerosis.

Protein disulfide isomerase (PDI) involves cell survival and death. Whether PDI mediates mechanical stretch stress (SS) and/or advanced glycosylation end products (AGEs) -triggered simultaneous increases in proliferation and apoptosis of vascular smooth muscle cells (VSMCs) is unknown. Here, we hypothesized that different expression levels of PDI trigger completely opposite cell fates among the different VSMC subtypes. Mouse veins were grafted into carotid arteries of non-diabetic and diabetic mice for 8 weeks; the grafted veins underwent simultaneous increases in proliferation and apoptosis, which triggered vein graft arterializations in non-diabetic or atherosclerosis in diabetic mice. A higher rate of proliferation and apoptosis was seen in the diabetic group. SS and/or AGEs stimulated the quiescent cultured VSMCs, resulting in simultaneous increases in proliferation and apoptosis; they could induce increased PDI activation and expression. Both in vivo and in vitro, the proliferating VSMCs indicated weak co-expression of PDI and SM-α-actin while apoptotic or dead cells showed strong co-expression of both. Either SS or AGEs rapidly upregulated the expression of PDI, NOX1 and ROS, and their combination had synergistic effects. Inhibiting PDI simultaneously suppressed the proliferation and apoptosis of VSMCs, while inhibition of SM-α-actin with cytochalasin D led to increased apoptosis and cleaved caspases-3 but had no effect on proliferation. In conclusion, different expression levels of PDI in VSMCs induced by SS and/or AGEs triggered a simultaneous increase in proliferation and apoptosis, accelerated vein graft arterializations or atherosclerosis, leading us to propose PDI as a novel target for the treatment of vascular remodeling and diseases.

Combined analysis of mRNA and miRNA identifies dehydration and salinity responsive key molecular players in citrus roots.

Citrus is one of the most economically important fruit crops around world. Drought and salinity stresses adversely affected its productivity and fruit quality. However, the genetic regulatory networks and signaling pathways involved in drought and salinity remain to be elucidated. With RNA-seq and sRNA-seq, an integrative analysis of miRNA and mRNA expression profiling and their regulatory networks were conducted using citrus roots subjected to dehydration and salt treatment. Differentially expressed (DE) mRNA and miRNA profiles were obtained according to fold change analysis and the relationships between miRNAs and target mRNAs were found to be coherent and incoherent in the regulatory networks. GO enrichment analysis revealed that some crucial biological processes related to signal transduction (e.g. 'MAPK cascade'), hormone-mediated signaling pathways (e.g. abscisic acid- activated signaling pathway'), reactive oxygen species (ROS) metabolic process (e.g. 'hydrogen peroxide catabolic process') and transcription factors (e.g., 'MYB, ZFP and bZIP') were involved in dehydration and/or salt treatment. The molecular players in response to dehydration and salt treatment were partially overlapping. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis further confirmed the results from RNA-seq and sRNA-seq analysis. This study provides new insights into the molecular mechanisms how citrus roots respond to dehydration and salt treatment.

[Identification of Pummelo Cultivars Based on Hyperspectral Imaging Technology].

Existing methods for the identification of pummelo cultivars are usually time-consuming and costly, and are therefore inconvenient to be used in cases that a rapid identification is needed. This research was aimed at identifying different pummelo cultivars by hyperspectral imaging technology which can achieve a rapid and highly sensitive measurement. A total of 240 leaf samples, 60 for each of the four cultivars were investigated. Samples were divided into two groups such as calibration set (48 samples of each cultivar) and validation set (12 samples of each cultivar) by a Kennard-Stone-based algorithm. Hyperspectral images of both adaxial and abaxial surfaces of each leaf were obtained, and were segmented into a region of interest (ROI) using a simple threshold. Spectra of leaf samples were extracted from ROI. To remove the absolute noises of the spectra, only the date of spectral range 400~1000 nm was used for analysis. Multiplicative scatter correction (MSC) and standard normal variable (SNV) were utilized for data preprocessing. Principal component analysis (PCA) was used to extract the best principal components, and successive projections algorithm (SPA) was used to extract the effective wavelengths. Least squares support vector machine (LS-SVM) was used to obtain the discrimination model of the four different pummelo cultivars. To find out the optimal values of σ2 and γ which were important parameters in LS-SVM modeling, Grid-search technique and Cross-Validation were applied. The first 10 and 11 principal components were extracted by PCA for the hyperspectral data of adaxial surface and abaxial surface, respectively. There were 31 and 21 effective wavelengths selected by SPA based on the hyperspectral data of adaxial surface and abaxial surface, respectively. The best principal components and the effective wavelengths were used as inputs of LS-SVM models, and then the PCA-LS-SVM model and the SPA-LS-SVM model were built. The results showed that 99.46% and 98.44% of identification accuracy was achieved in the calibration set for the PCA-LS-SVM model and the SPA-LS-SVM model, respectively, and a 95.83% of identification accuracy was achieved in the validation set for both the PCA-LS-SVM and the SPA- LS-SVM models, which were built based on the hyperspectral data of adaxial surface. Comparatively, the results of the PCA-LS-SVM and the SPA-LS-SVM models built based on the hyperspectral data of abaxial surface both achieved identification accuracies of 100% for both calibration set and validation set. The overall results demonstrated that use of hyperspectral data of adaxial and abaxial leaf surfaces coupled with the use of PCA-LS-SVM and the SPA-LS-SVM could achieve an accurate identification of pummelo cultivars. It was feasible to use hyperspectral imaging technology to identify different pummelo cultivars, and hyperspectral imaging technology provided an alternate way of rapid identification of pummelo cultivars. Moreover, the results in this paper demonstrated that the data from the abaxial surface of leaf was more sensitive in identifying pummelo cultivars. This study provided a new method for to the fast discrimination of pummelo cultivars.

Relationships between genetic polymorphisms of triggering receptor expressed on myeloid cells-1 and septic shock in a Chinese Han population.

BACKGROUND: Triggering receptor expressed on myeloid cells-1 (TREM-1) is a cell surface receptor expressed on neutrophils and monocytes. TREM-1 acts to amplify inflammation and serves as a critical mediator of inflammatory response in the context of sepsis. To date, the predisposition of TREM-1 gene polymorphisms to septic shock has not been reported. This study was designed to investigate whether TREM-1 genomic variations are associated with the development of septic shock. METHODS: We genotyped two TREM-1 single nucleotide polymorphisms (SNPs, rs2234237 and rs2234246) and evaluated the relationships between these SNPs and septic shock on susceptibility and prognosis. RESULTS: TREM-1 rs2234246 A allele in the promoter region was significantly associated with the susceptibility of septic shock in recessive model (AA, OR=3.10, 95%CI 1.15 to 8.32, P=0.02), and in codominant model (AG, OR=0.72, 95%CI 0.43-1.19, P=0.02; AA, OR=2.71, 95%CI 1.00-7.42; P=0.03). However, in three inherited models (dominant model, recessive model, and codominant model), none of the assayed loci was significantly associated with the prognosis of septic shock. The non-survivor group demonstrated higher plasma IL-6 levels (99.7±34.7 pg/mL vs. 61.2±26.5 pg/mL, P<0.01) than the survivor group. Plasma concentrations of IL-6 among the three genotypes of rs2234246 were AA 99.4±48.9 pg/mL, AG 85.4±43 pg/mL, and GG 65.3±30.7 pg/mL (P<0.01). The plasma concentrations of IL-6 in patients with AA genotypes were significantly higher than those in patients with GG genotypes (P<0.01). CONCLUSION: TREM-1 genetic polymorphisms rs2234246 may be significantly correlated only with susceptibility to septic shock in the Chinese Han population.

Comprehensive analysis of SAUR gene family in citrus and its transcriptional correlation with fruitlet drop from abscission zone A.

Small auxin-up RNA (SAUR) gene family is large, and the members of which can be rapidly induced by auxin and encode highly unstable mRNAs. SAUR genes are involved in various developmental and physiological processes, such as leaf senescence, fruitlet abscission, and hypocotyl development. However, their modes of action in citrus remain unknown. Hereby, a systematic analysis of SAUR gene family in citrus was conducted through a genome-wide search. In this study, a total of 70 SAUR genes, referred to as CitSAURs, have been identified in citrus. The evolutionary relationship and the intro-exon organization were analyzed, revealing strong gene conservation and the expansion of particular functional genes during plant evolution. Expression analysis showed that the major of CitSAUR genes were expressed in at least one tissue and showed distinctive expression levels, indicating the SAUR gene family play important roles in the development and growth of citrus organs. However, there were more than 20 CitSAUR genes such as CitSARU36, CitSAUR37, and CitSAUR54 exhibiting very low expression level in all tissue tested. Twenty-three out of 70 CitSAUR genes were responded to indole-3-acetic acid (IAA) treatment, of which just CitSAUR19 was down-regulated. Additionally, 14 CitSAUR genes exhibited distinct changes during fruitlet abscission, however just 5 of them including CitSAUR06, CitSAUR08, CitSAUR44, CitSAUR61, and CitSAUR64 were associated with fruitlet abscission. The current study provides basic information for the citrus SAUR gene family and will pave the way for deciphering the precise role of SAURs in citrus development and growth as well as fruitlet abscission.

The ARF, AUX/IAA and GH3 gene families in citrus: genome-wide identification and expression analysis during fruitlet drop from abscission zone A.

Completion of the whole genome sequencing of citrus enabled us to perform genome-wide identification and functional analysis of the gene families involved in agronomic traits and morphological diversity of citrus. In this study, 22 CitARF, 11 CitGH3 and 26 CitAUX/IAA genes were identified in citrus, respectively. Phylogenetic analysis revealed that all the genes of each gene family could be subdivided into three groups and showed strong evolutionary conservation. The GH3 and AUX/IAA gene families shrank and ARF gene family was highly conserved in the citrus genome after speciation from Arabidopsis thaliana. Tissue-specific expression profiles revealed that 54 genes were expressed in at least one tissue while just 5 genes including CitARF07, CitARF20, CitGH3.04, CitAUX/IAA25 and CitAUX/IAA26 with very low expression level in all tissues tested, suggesting that the CitARF, CitGH3 and CitAUX/IAA gene families played important roles in the development of citrus organs. In addition, our data found that the expression of 2 CitARF, 4 CitGH3 and 4 AUX/IAA genes was affected by IAA treatment, and 7 genes including, CitGH3.04, CitGH3.07, CitAUX/IAA03, CitAUX/IAA04, CitAUX/IAA18, CitAUX/IAA19 and CitAUX/IAA23 were related to fruitlet abscission. This study provides a foundation for future studies on elucidating the precise role of citrus ARF, GH3 and AUX/IAA genes in early steps of auxin signal transduction and open up a new opportunity to uncover the molecular mechanism underlying citrus fruitlet abscission.

Genome-wide analysis of citrus R2R3MYB genes and their spatiotemporal expression under stresses and hormone treatments.

The R2R3MYB proteins represent one of the largest families of transcription factors, which play important roles in plant growth and development. Although genome-wide analysis of this family has been conducted in many species, little is known about R2R3MYB genes in citrus, In this study, 101 R2R3MYB genes has been identified in the citrus (Citrus sinesis and Citrus clementina) genomes, which are almost equal to the number of rice. Phylogenetic analysis revealed that they could be subdivided into 21 subgroups. The evolutionary relationships and the intro-exon organizations were also analyzed, revealing strong gene conservation but also the expansions of particular functional genes during the plant evolution. Tissue-specific expression profiles showed that 95 citrus R2R3MYB genes were expressed in at least one tissue and the other 6 genes showed very low expression in all tissues tested, suggesting that citrus R2R3MYB genes play important roles in the development of all citrus organs. The transcript abundance level analysis during abiotic conditions (NaCl, abscisic acid, jasmonic acid, drought and low temperature) identified a group of R2R3MYB genes that responded to one or multiple treatments, which showed a promising for improving citrus adaptation to stresses. Our results provided an essential foundation for the future selection of the citrus R2R3MYB genes for cloning and functional dissection with an aim of uncovering their roles in citrus growth and development.

[Determination of photosynthetic pigments in citrus leaves based on hyperspectral images datas].

The effective region was segmented from the hyperspectral image of citrus leaf by threshold method with the average spectrum extracted and used to describe the corresponding leaf. Based on the different spectral pre-processing methods, the prediction models of three photosynthetic pigments (i. e., chlorophyll a, chlorophyll b, and carotenoid) were calibrated by partial least squares (PLS), BP neural network (BPNN) and least square support vector machine (LS-SVM). The LS-SVM model for chlorophyll a was established based on multiplicative scatter correction (MSC), and the correlation coefficient (Rp) and the root mean square error of prediction (RMSEP) were 0.898 3 and 0.140 4, respectively. The LS-SVM model for chlorophyll b with Rp = 0.912 3 and RMSEP = 0.042 6, was established based on standard normal variable (SNV). The PLS model for carotenoid was established with Rp = 0.712 8 and RMSEP = 0.062 4 based on moving average smoothing (MAS), but the result was no better than the other two. The results illustrated that these three photosynthetic pigments could be nondestructively and real time estimated by hyperspectral image.

[Identification of different Citrus sinensis (L.) Osbeck trees varieties using Fourier transform infrared spectroscopy and hierarchical cluster analysis].

Researched on diversity of the spring leaf samples of seven different Citrus sinensis (L.) Osbeck varieties by Fourier transform infrared (FTIR) spectroscopy technology, the results showed that the Fourier transform infrared spectra of seven varieties leaves was composited by the absorption band of cellulose and polysaccharide mainly, the wave number of characteristics absorption peaks were similar at their FTIR spectra. However, there were some differences in shape of peaks and relatively absorption intensity. The conspicuous difference was presented at the region between 1 500 and 700 cm(-1) by second derivative spectra. Through the hierarchical cluster analysis (HCA) of second derivative spectra between 1 500 and 700 cm(-1), the results showed that the clustering of the different varieties of Citrus sinensis (L.) Osbeck varieties was classification according to genetic relationship. The results showed that FTIR spectroscopy combined with hierarchical cluster analysis could be used to identify and classify of citrus varieties rapidly, it was an extension method to study on early leaves of varieties orange seedlings.

[Study on synchronous correlation between fruit characteristic spectrum and the parameter of internal quality for Hamlin sweet orange fruit].

The purpose of our study is to study the relationship between the reflective spectrum of fruit and the internal quality of the orange fruit and find the suitable mark spectrum that can synchronously measure the several fruit quality index at same time to lay a foundation for the development of a rapid and nondestructive field fruit quality analysis technique by analyzing the visible-near infrared spectrum. Mature Hamlin orange (Citrus sinensis (L)cv. Hamlin sweet orange) fruits were individually mensurated for their reflective spectrum by using FieldSpec-HH spectrometer and for their contents of total soluble solid (TSS), citric acid and vitamin C (Vc) by chemistry analysis. The experiment results showed that the fruit reflectivity values (x) at 988 nm was significantly correlated to both TSS (y)(r = 0.387* *, y = 13. 957x + 5.405), TSS/acid ratio(y)(r = 0. 440* *, y = 75.120x + 37.256), and Vc(r = 0.309*). Both of TSS and Vc contends were positively correlated with the second derivatives of the reflective spectrum at 943 nm, with correlation coefficients of 0.339* and 0.355*. TSS/acid ratio was positively correlated only with the reciprocal log values of the reflective spectrum at 944 nm (r = 0.304*). The results in this study indicated that fruit quality indexes TSS, Vc and TSS/acid can be synchronously, rapidly and nondestructively field measured at the same time by the 988 or 429 nm reflective spectrum test and special regress equation operation.

[Research on zinc content in leaf of Olinda Valencia orange using visible near infrared spectroscopy model].

Olinda valencia orange leaves dry powder-like were taken as sample, and chemical analysis combined with technology of visible near-infrared spectroscopy (Vis/NIRS) was used, through the treatment process of second derivative spectrum of samples of the original spectrum and denoising (Noise). Meanwhile, method of partial least squares (PLS) and cross-validation were used to establish maths model of Zn concentration which applying band combination composited by 400-500 and 1201-1300 nm of characteristic wavelength band. The coefficient of establishing models is 0.9975, while the coefficient of correlation coefficient of prediction is 0.9920. The root mean square error of prediction (RMSEP) of cross-validation is 0.5868. Therefore, the means using visible near-infrared spectroscopy (Vis/NIRS) and the methods of cross-validation and PLS to establish the spectral correction model reflecting the Zn content in leaves and characteristic wavelength bands can detect the Zn content in citrus leaves quantitatively and quickly.