Correlation between plant cell wall stiffening and root extension arrest phenotype in the combined abiotic stress of Fe and Al.

The plasticity and growth of plant cell walls (CWs) remain poorly understood at the molecular level. In this work, we used atomic force microscopy (AFM) to observe elastic responses of the root transition zone of 4-day-old Arabidopsis thaliana wild-type and almt1-mutant seedlings grown under Fe or Al stresses. Elastic parameters were deduced from force-distance curve measurements using the trimechanic-3PCS framework. The presence of single metal species Fe2+ or Al3+ at 10 µM exerts no noticeable effect on the root growth compared with the control conditions. On the contrary, a mix of both the metal ions produced a strong root-extension arrest concomitant with significant increase of CW stiffness. Raising the concentration of either Fe2+ or Al3+ to 20 µM, no root-extension arrest was observed; nevertheless, an increase in root stiffness occurred. In the presence of both the metal ions at 10 µM, root-extension arrest was not observed in the almt1 mutant, which substantially abolishes the ability to exude malate. Our results indicate that the combination of Fe2+ and Al3+ with exuded malate is crucial for both CW stiffening and root-extension arrest. However, stiffness increase induced by single Fe2+ or Al3+ is not sufficient for arresting root growth in our experimental conditions.

Surgical treatment of nasopharyngeal cancer - a consensus recommendation from two Chinese associations.

BACKGROUND: Surgical treatment is playing an increasingly important role in the management of nasopharyngeal carcinoma (NPC). This consensus focuses on the indications for optimal surgery, and surgical methods in the whole process of treatment for NPC to provide a useful reference to assist these difficult clinical decisions. METHODOLOGY: A thorough review of available literature on NPC and surgery was conducted by the Association for the prevention and treatment of nasopharyngeal carcinoma in China, international exchange and promotion Association for medicine and healthcare, and the Committee on nasopharyngeal cancer of Guangdong provincial anticancer association. A set of questions and a preliminary draft guideline was circulated to a panel of 1096 experienced specialists on this disease for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the experts in two authoritative medical science and technology academic groups in the prevention and treatment of NPC in China for review and reconsideration. RESULTS: The initial round of questions showed variations in clinical practice even among similar specialists, reflecting the lack of high-quality supporting data and resulting difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of surgery, including indications and surgical approaches. CONCLUSION: By standardizing the surgical indications and practice, we hope not only to improve the surgical outcomes, but also to highlight the key directions of future clinical research in the surgical management of NPC.

Innovative Clinical Scenario Simulator for Step-by-Step Microsurgical Training.

BACKGROUND: Microsurgical training should be implemented with consideration of operative difficulties that occur in actual clinical situations. We evaluated the effectiveness of a novel clinical scenario simulator for step-by-step microsurgical training that progressed from conventional training to escalated training with additional obstacles. METHODS: A training device was designed according to multiple and intricate clinical microsurgery scenarios. Twenty surgical residents with no experience in microsurgery were randomly assigned to either the control group (conventional training curricula, n = 10) or the experimental group (step-by-step training courses, n = 10). After 4 weeks of laboratory practice, the participants were scheduled to perform their first microvascular anastomoses on patients in an operating room. The Global Rating Scale (GRS) scores and operative duration were used to compare microsurgical skills between the two groups. RESULTS: There were no significant differences in the participants' baseline characteristics before microsurgical training between the groups with respect to age, sex, postgraduate year, surgical specialty, or mean GRS score (p < 0.05). There were also no significant differences in recipient sites between the two groups (p = 0.735). After training, the GRS scores in both groups were significantly improved (p = 0.000). However, in the actual microsurgical situations, the GRS scores were significantly higher in the experimental than control group (p < 0.05). There was no significant difference in the operative duration between the two groups (p < 0.13). CONCLUSION: Compared with a traditional training program, this step-by-step microsurgical curriculum based on our clinical scenario simulator results in significant improvement in acquisition of microsurgical skills.

[Safety and efficacy of acute stent implantation during endovascular treatment for patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis].

Objective: To investigate the efficacy and safety of acute stent implantation during endovascular treatment for patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis. Methods: A retrospective analysis was carried out on 46 patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis who received endovascular treatment at the Strategic Support Force Medical Center from January 2015 to August 2022. Twenty-seven patients underwent balloon angioplasty alone and 19 patients underwent acute stent implantation. The baseline characteristics, modified thrombolysis in cerebral infarction (mTICI) score of the responsible vessels, modified Rankin scale (mRS) score 90 days after operation, incidence of symptomatic intracranial hemorrhage and mortality of the two groups were evaluated. Results: The proportion of effective recanalization of the offending vessels (mTICI≥2b) in the acute stenting group was slightly higher than that in the balloon angioplasty group (16/19 vs. 81.5%), but the difference was not statistically significant (P>0.05). Besides, there was no significant difference in the median of mRS between the acute stenting group [3.0(0, 4.0)] and the balloon angioplasty group [4.0(1.0, 5.0)] 90 days after operation (P>0.05). In terms of safety, the incidence of symptomatic intracranial hemorrhage and mortality were comparable between the two groups (P>0.05). Conclusions: The effect of acute stent implantation during endovascular treatment for patients with emergent large vessel occlusion due to intracranial atherosclerotic stenosis is not inferior to that of balloon angioplasty, and it does not increase the risk of intracranial bleeding complications.

[Association, differences, and applications of three commonly used statistical indicators: risk ratio, hazard ratio, and odds ratio].

Relative Risk (RR), Hazard Ratio (HR), and Odds Ratio (OR) are commonly used statistical measures in the field of public health to assess the magnitude of the effect of exposure factors on outcomes. These indicators have different calculation principles and implications in public health. However, a few researchers misused or misinterpreted RR, HR, and OR values when interpreting study results. Therefore, this article explores the relationships and differences among these measures, as well as the correct selection and application of RR, HR, and OR in both cohort study and case-control study.

Cry11Aa and Cyt1Aa exhibit different structural orders in crystal topography.

Cry11Aa and Cyt1Aa are two pesticidal toxins produced by Bacillus thuringiensis subsp. israelensis. To improve our understanding of the nature of their oligomers in the toxic actions and synergistic effects, we performed the atomic force microscopy to probe the surfaces of their natively grown crystals, and used the L-weight filter to enhance the structural features. By L-weight filtering, molecular sizes of the Cry11Aa and Cyt1Aa monomers obtained are in excellent agreement with the three-dimensional structures determined by x-ray crystallography. Moreover, our results show that the layered feature of a structural element distinguishes the topographic characteristics of Cry11Aa and Cyt1Aa crystals, suggesting that the Cry11Aa toxin has a better chance than Cyt1Aa for multimerization and therefore cooperativeness of the toxic actions.

[Safety and efficacy of intra-arterial tirofiban infusion in patients with acute cardiogenic cerebral embolism undergoing endovascular reperfusion therapy].

Objective: To evaluate the safety and efficacy of intra-arterial tirofiban infusion during endovascular reperfusion therapy in patients with acute cardiogenic cerebral embolism. Methods: Clinical data of 72 patients with acute cardiogenic cerebral embolism caused by large artery occlusion were retrospectively analyzed in Department of Neurology, Strategic Support Force Medical Center from August 2015 to August 2020.Among those, 52 patients were treated with intra-arterial tirofiban, the other 20 patients were treated with control medication. The baseline characteristics, modified thrombolysis in cerebral infarction (mTICI) score of responsible vessels, modified Rankin scale (mRS) score 90 days after operation, incidence of symptomatic intracranial hemorrhage and mortality were evaluated and compared in two groups. Results: The proportion of effective recanalization of the offending vessels (mTICI≥2b) in tirofiban group was higher than that in control group (92.3% vs. 75.0%), but the difference was not statistically significant (P=0.104). At 90 days after operation, the rate of patients with good prognosis (mRS≤2) in tirofiban group (61.5%) was significantly higher than that in control group (35.0%) (P<0.05). The incidence of symptomatic intracranial hemorrhage and mortality were comparable between the two groups (P>0.05). Conclusion: Intra-arterial tirofiban infusion in patients with acute cardiogenic cerebral embolism is effective and feasible, which improves the prognosis without increasing the risk of intracranial bleeding complications.

[Clinicopathological and molecular features of multinodular and vacuolating neuronal tumors of the cerebrum].

Objective: To investigate clinicopathological features of multinodular and vacuolar neurodegenerative tumor (MVNT) of the cerebrum, and to investigate its immunophenotype, molecular characteristics and prognosis. Methods: Four cases were collected at the General Hospital of Southern Theater Command, Guangzhou, China and one case was collected at the First People's Hospital of Huizhou, China from 2013 to 2021. Clinical, histological, immunohistochemical and molecular characteristics of these five cases were analyzed. Follow-up was carried out to evaluate their prognoses. Results: There were four females and one male, with an average age of 42 years (range, 17 to 51 years). Four patients presented with seizures, while one presented with discomfort on the head. Pre-operative imaging demonstrated non-enhancing, T2-hyperintense multinodular lesions in the deep cortex and superficial white matter of the frontal (n=1) or temporal lobes (n=4). Microscopically, the tumor cells were mostly arranged in discrete and coalescent nodules primarily within the deep cortical ribbon and superficial subcortical white matter. The tumors were composed of large cells with ganglionic morphology, vesicular nuclei, prominent nucleoli and amphophilic or lightly basophilic cytoplasm. They exhibited varying degrees of matrix vacuolization. Vacuolated tumor cells did not show overt cellular atypia or any mitotic activities. Immunohistochemically, tumor cells exhibited widespread nuclear staining for the HuC/HuD neuronal antigens, SOX10 and Olig2. Expression of other neuronal markers, including synaptophysin, neurofilament and MAP2, was patchy to absent. The tumor cells were negative for NeuN, GFAP, p53, H3K27M, IDH1 R132H, ATRX, BRG1, INI1 and BRAF V600E. No aberrant molecular changes were identified in case 3 and case 5 using next-generation sequencing (including 131 genes related to diagnosis and prognosis of central nervous system tumors). All patients underwent complete or substantial tumor excision without adjuvant chemoradiotherapy. Post-operative follow-up information over intervals of 6 months to 8 years was available for five patients. All patients were free of recurrence. Conclusions: MVNT is an indolent tumor, mostly affecting adults, which supports classifying MVNT as WHO grade 1. There is no tumor recurrence even in the patients treated with subtotal surgical excision. MVNTs may be considered for observation or non-surgical treatments if they are asymptomatic.

[Advances in MRI research on extraocular muscles and pulleys].

With the continuous development of imaging technology, high-resolution magnetic resonance imaging (MRI) can be used to quantitatively analyze the morphological and functional status of orbital soft tissue. Changes in the morphology and function of the extraocular muscles and pulleys may be the mechanical basis of some incomitant and special patterns of strabismus. Recent MRI research advances related to the characteristics of extraocular muscles and pulleys of healthy people and strabismic patients are reviewed in this article.

Intrinsically Disordered Tardigrade Proteins Self-Assemble into Fibrous Gels in Response to Environmental Stress.

Tardigrades are remarkable for their ability to survive harsh stress conditions as diverse as extreme temperature and desiccation. The molecular mechanisms that confer this unusual resistance to physical stress remain unknown. Recently, tardigrade-unique intrinsically disordered proteins have been shown to play an essential role in tardigrade anhydrobiosis. Here, we characterize the conformational and physical behaviour of CAHS-8 from Hypsibius exemplaris. NMR spectroscopy reveals that the protein comprises an extended central helical domain flanked by disordered termini. Upon concentration, the protein is shown to successively form oligomers, long fibres, and finally gels constituted of fibres in a strongly temperature-dependent manner. The helical domain forms the core of the fibrillar structure, with the disordered termini remaining highly dynamic within the gel. Soluble proteins can be encapsulated within cavities in the gel, maintaining their functional form. The ability to reversibly form fibrous gels may be associated with the enhanced protective properties of these proteins.

[Diagnosis and treatment of Chlamydia psittaci pneumonia: experiences of 8 cases].

Objective: In order to improve the understanding and clinical treatment of Chlamydia psittaci pneumonia, we analyzed the clinical manifestations, laboratory test results and imaging features of 8 patients. Methods: We collected the clinical data of 8 patients with Chlamydia psittaci pneumonia diagnosed by metagenomic next-generation-sequencing (mNGS) from November 2018 to February 2020, including clinical features, chest CT scan, pathological features and antibiotic use. Results: A total of one male and 7 females, aged from 45 to 85 years(median 62 years), were included in this study. All the patients had high fever, cough and most had expectoration (6/8). The leukocyte count and PCT level were mostly normal (7/8). However, we observed decreased lymphocyte count(5/8), elevated C-reactive protein in all patients, and increased ESR in most patients (7/8). The chest CT of all the patients showed large patchy consolidation, with one case having pleural effusion. The pathological manifestations were nonspecific, showing infiltration of inflammatory cells and exudation. Moxifloxacin and/or doxycycline were administered after diagnosis, and the course of treatment lasted from 14 to 21 days.Chest CT showed absorption of lesions following treatment Conclusions: Chlamydia psittaci pneumonia showed certain characteristics, including high fever with pulmonary patchy consolidation, and normal white blood cell count. Molecular diagnostic methods such as mNGS could lead to rapid diagnosis and treatment which can shorten the course of hospitalization and thus improve prognosis.

[The correlations between C-reactive protein to albumin ratio and postoperative complications in patients with colorectal surgery].

Objective: To examine the correlations of C-reactive protein (CRP)/albumin ratio (CAR) with the postoperative complications of patients with colorectal cancer. Methods: The clinic data of 312 patients undergoing elective surgery for colorectal cancer in Hainan Hospital of People's Liberation Army General Hospital between January 2013 and July 2018 was analyzed retrospectively. There were 188 males and 124 females, aged (61.0±12.9) years (range: 21 to 86 years). Logistic analysis was used to identify relative factors for postoperative complications. Receiver operating characteristic curves were developed to examine the cutoff values and compare diagnostic accuracy of the CAR and CRP levels. Results: Postoperative complications occured in 28.5% (89/312) cases. Hemoglobin on postoperative day(POD) 3 (OR=0.977, 95% CI: 0.957 to 0.998, P=0.034), preoperative CRP (OR=1.209, 95% CI: 1.055 to 1.386, P=0.006) and CAR on POD 3 (OR=0.033, 95% CI: 0.016 to 0.067, P<0.01) were found to be significant independent relative factors for postoperative complications. The cutoff point of CAR on POD 3 was 0.325, patients with CAR≥0.325 were found to have more postoperative complications than those with CAR<0.325. The area under the curve of CAR on POD 3 and preoperative CRP were 0.872, 0.626, respectively. The positive predictive value of CAR on POD 3 was higher than that of preoperative CRP (79.9% vs. 55.1%). Conclusions: CAR is closely related to the occurrence of postoperative complications in colorectal surgery. Patients with CAR≥0.325 on POD 3 has higher incidence of postoperative complications.

Effect of conservative treatment in aortoiliac occlusive disease.

Objective: To determine the effect of primary conservative treatment without revascularization in patients with proven aortoiliac occlusive disease (AIOD) presenting with intermittent claudication (IC).Background: The initial treatment of IC should focus on supervised exercise therapy (SET) and pharmacotherapy. Nowadays, primary endovascular revascularization (EVR) has become increasingly popular in patients with all types of AIOD. But in daily practice, EVR is often performed without initially extensive exercise.Method: This is a single centre retrospective study from December 2012 to September 2017. Primary outcomes were maximum walking distance (MWD) and patient satisfaction. Secondary outcomes were revascularization rate and mortality.Results: Twenty-four patients were included. Mean age was 64 years (SD: 9). Mean follow-up was 28 months (SD: 17). Nineteen patients (80%) had SET. In 18 (75%) patients, the MWD was improved compared to the initial situation. In five (21%) patients, the MWD stayed the same. The MWD of one (4%) patient decreased. Overall satisfaction rate was 87%. Three patients (13%) were not satisfied with the conservative treatment and eventually got an EVR. There was no disease related death.Conclusions: Conservative treatment, especially with SET, has acceptable subjective symptom outcomes in selected patients with AIOD. It could be a good alternative treatment for certain patients with AIOD and IC.

[Transcriptome analysis of "Langmei" fruits and key enzyme genes structure and function prediction involved in citric acid biosynthesis].

Prunus mume "Langmei" is a relict tree species, which fruit has good medicinal value. To understand the biosynthesis pathway of citric acid, the Illumina HiSeq XTen high-throughput sequencing technology was used to get the transcriptome from "Langmei". A total of 38 936 unigenes were obtained by assembling the fruit transcripts, of which 28 311 unigenes were successfully annotated in public databases, 15 193 unigenes were mapped to 265 KEGG metabolic pathways, and 18 908 unigenes were classified into 59 GO functional subclasses, 103 unigenes encoding 15 key enzymes involved in citric acid synthesis pathway were identified and analyzed. The structural model of citrate synthetase in "Langmei" showed that it was a homodimer and the secondary structure of each monomer was mainly composed of alpha helixes. Moreover, the residues in the active site of the citrate synthetase were highly conserved. This study provides a valuable resource for identifying candidate genes involved in the citric acid biosynthesis pathway, and will promote the development and sustainable utilization of genetic resources of "Langmei".

Infection with sodA mutant of S. Typhimurium leads to up-regulation of autophagy in Raw264·7 macrophages.

Salmonella enterica serovar Typhimurium (S. Typhimurium) inhabits a wide range of hosts, including poultry, and causes acute gastroenteritis in humans that may result in death. Superoxide dismutase (SOD) is an important antioxidant enzyme present in nearly all living cells exposed to oxygen. Recently, we reported the novel roles of SOD in serum resistance and biofilm formation in S. Typhimurium. This study was designed to explore the effect of infection with sodA mutant of S. Typhimurium on the autophagic response of macrophages. Murine macrophage cell line RAW264·7 was infected with wild-type (LSM52), a sodA deletion mutant (LSM52ΔsodA) and complemented strain (LSM52CΔsodA). We found that sodA deletion triggered remarkable autophagic responses in infected cells, shown as higher concentrations of LC3-II or Beclin-1 than those infected with the wild-type or complemented strain during the first hour post-infection in S. Typhimurium. Consistent with these results, the number of viable bacteria in cells infected with the sodA mutant was significantly lower than those infected with wild-type or complemented strains at 1 h, 2 h and 3 h post-infection in S. Typhimurium. All results indicated that infection with sodA mutant of S. Typhimurium leads to up-regulation of autophagy in Raw264·7 macrophages. SIGNIFICANCE AND IMPACT OF THE STUDY: Autophagy plays an important role in Salmonella infection although the role of autophagy in Salmonella infection remains unclear. This study was designed to explore the effect of sodA on the autophagic response of macrophage. We found that infection with sodA mutant of Salmonella Typhimurium could lead to up-regulation of autophagy in Raw264·7 macrophages.

[The effect of trabeculectomy combined with prophylactic sclerotomy as a treatment of late stage juvenile open angle glaucoma and primary congenital glaucoma patients: a primary observational study].

Objective: To evaluate the outcomes of trabeculectomy combined with a new prophylactic sclerotomy in late stage juvenile open angle glaucoma (JOAG) and primary congenital glaucoma (PCG) patients at high risks of intraoperative and postoperative suprachoroidal hemorrhage (SCH). Method: A retrospective case series study. Thirty-three eyes of 28 JOAG patients and 15 eyes of 12 PCG patients with high risk factors for severe choroidal effusion or SCH were enrolled from November 2006 to April 2012 at Eye and ENT Hospital of Fudan University. The standard trabeculectomy accompanied by prophylactic sclerotomy was performed (video attached). Ophthalmic examinations were performed before and after the surgery. Surgical outcome was assessed in terms of intraocular pressure (IOP), best-corrected visual acuity, optic nerve head cup disc ratio, visual field, and complications. All patients were followed up for at least 1 year. Complete success was defined as an IOP ≥6 mmHg (1 mmHg=0.133 kPa) but ≤18 mmHg without medication. Qualified success was defined as an IOP ≥6 mmHg but ≤18 mmHg with local application of medications. Kaplan-Meier survival curves were drawn for the success rate calculation. Results: The mean age of all 40 patients was (13.2±9.4) years old. And among them, 22 patients were male and 18 patients were female. The mean follow-up time was (31.8±15.9) months. At the postoperative 3(rd) year, the complete success rate was 75.8%, and the qualified success rate was 90.0%. In our case series, one eye had expulsive SCH intraoperatively and two eyes had delayed SCH postoperatively. All of them were successfully saved without further surgery and with no significant damage to visual function. Conclusion: Trabeculectomy combined with prophylactic sclerotomy is a promising technique developed to control IOP in late stage JOAG and PCG patients, which provides a potential intervention to reduce severe consequences of massive choroidal effusion or SCH. (Chin J Ophthalmol, 2019, 55: 347-354).

[Association between resting heart rate trajectory pattern and risk of cardiovascular and cerebrovascular diseases].

Objective: To examine whether the long-term resting heart rate (RHR) pattern can predict the risk of cardiovascular and cerebrovascular diseases (CVDs). Methods: This prospective cohort study included 63 040 participants who took part in the health examination in 2006 and one of the health examinations on 2008 or 2010 and were free of myocardial infarction, stroke, arrhythmia, cancer and not treated with ß-recepter blocker. The outcomes were the first occurrence of myocardial infarction and stroke during the follow up ended on December 31, 2015. RHRs were measured in 2006, 2008, and 2010. We used latent mixture modeling SAS Proc procedure to identify RHR trajectories. We identified 4 distinct RHR trajectory patterns based on the data derived from 2006 and on the pattern change during 2006 to 2010 (low-stable, moderate-stable, moderate-increasing, elevated-decreasing). Collected the general clinical data of the patients. Cox regression model was used to determine the association between RHR trajectory patterns and the risk of CVDs during follow up. Hazard ratio (HR) with 95% confidence intervals (CI) were calculated using Cox regression modeling. Results: There were statistical significance among the 4 distinct RHR trajectory patterns on the following variables: age, gender, smoking status, drinking status, physical activity, education status, history of use antihypertensive drugs, history of hypertension,history of diabetes, body mass index, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting blood glucose, and the level of high-sensitivity C-reactive protein (all P<0.01). The moderate-increasing pattern experienced the highest risk of developing stroke and CVDs among all 4 patterns. The cumulative incidence of cerebral infarction, cerebral hemorrhage and CVDs in the order of low-stable trajectory, moderate-stable trajectory and moderate-increasing trajectory. The cumulative incidences of cerebral infarction, cerebral hemorrhage and CVDs in elevated-decreasing trajectory group were significantly lower than those in moderate-increasing trajectory group, but higher than those in moderate-stable trajectory group. Compared to the low-stable pattern, adjusted HR was 1.3 (95%CI 1.0-1.6) for the moderate-increasing pattern after adjustment for potential confounders. Conclusion: Our study finds that individuals with moderate-increasing RHR trajectory pattern are associated with higher risk of cardiovascular and CVDs.

ILC2 frequency and activity are inhibited by glucocorticoid treatment via STAT pathway in patients with asthma.

BACKGROUND: Group 2 innate lymphoid cells (ILC2s) were closely associated with asthma. However, there were no perspective studies about the effects of glucocorticoid on ILC2s in asthma patients. Our objective was to perform a perspective study and evaluate the ILC2 activity after glucocorticoid therapy in asthma patients. METHODS: The asthma and asthma with allergic rhinitis patients were treated with glucocorticoid for 3 months. The circulating ILC2 levels were evaluated. The effects of glucocorticoid on ILC2s and possible signalling pathways were investigated in vitro. RESULTS: The patients were well-controlled, and the high ILC2 levels were significantly decreased at 1 and 3 months after treatment. Peripheral blood monocytes from allergic patients produced dramatic IL-5, IL-13 and IL-9 in response to IL-25, IL-33 plus IL-2, and glucocorticoid significantly decreased their levels. Moreover, ILC2s were identified to be the predominant source of IL-5, IL-13 and IL-9, and glucocorticoid treatment was able to reverse their high levels. STAT3, STAT5, STAT6, JAK3 and MEK signalling pathways were proved to be involved in regulating ILC2 activity under the glucocorticoid treatment. CONCLUSION: The data suggested that glucocorticoid administration could be effective in treating asthma by regulating ILC2s via MEK/JAK-STAT signalling pathways. This provides a new understanding of glucocorticoid application in regard to allergic diseases.

A novel near-infrared nanomaterial with high quantum efficiency and its applications in real time in vivo imaging.

Fluorescence imaging signal is severely limited by the quantum efficiency and emission wavelength. To overcome these challenges, novel NIR-emitting K5NdLi2F10 nanoparticles under NIR excitation was introduced as fluorescence imaging probe for the first time. The photostability of K5NdLi2F10 nanoparticles in the water, phosphate buffer saline, fetal bovine serum and living mice was investigated. The fluorescence signal was detected with depths of 3.5 and 2.0 cm in phantom and pork tissue, respectively. Fluorescence spectrum with a significant signal-to-background ratio of 10:1 was captured in living mice. Moreover, clear NIR images were virtualized for the living mice after intravenous injection. The imaging ability of nanoparticles in tumor-beard mice were evaluated, the enrichment of K5NdLi2F10 nanoparticles in tumor site due to the enhanced permeability and retention effect was confirmed. The systematic studies of toxicity, bio-distribution and in-vivo dynamic imaging suggest that these materials give high biocompatibility and low toxicity. These NIR-emitting nanoparticles with high quantum efficiency, high penetration and low toxicity might facilitate tumor identification in deep tissues more sensitively.

Functional analysis of superoxide dismutase of Salmonella typhimurium in serum resistance and biofilm formation.

AIMS: Further investigations of the novel biological functions of SodA in Salmonella enterica serovar typhimurium (Salm. typhimurium). METHODS AND RESULTS: A deletion mutant of sodA in Salm. typhimurium was constructed and its biological characteristics were analysed. More specifically, the roles of superoxide dismutase (SOD) in resistance to environmental stresses and serum, biofilm formation, epithelial cell adherence and invasion were investigated. Inactivation of sodA gene resulted in a slightly reduced growth rate, low SOD activity and increased susceptibility to reactive oxygen species and chicken serum. However, SodA was not involved in the motility of Salm. typhimurium. In addition, the sodA mutant exhibited a decreased capacity to form biofilm as well as to adhere and invade to HeLa cells, compared to the wild-type and complemented strains. CONCLUSIONS: Salmonella typhimurium SOD appears to play an important role in resistance to serum and oxidative stress, biofilm formation, adherence to and invasion of epithelial cells. SIGNIFICANCE AND IMPACT OF THE STUDY: This study illustrates the novel roles of SodA in serum resistance and biofilm formation in Salm. typhimurium, which may provide a candidate for the biofilm eradication and prevention of infections.