Preoperative optimization to prevent periprosthetic joint infection in at-risk patients

Periprosthetic joint infection (PJI) remains an important complication with devastating consequences after total joint arthroplasties. With the increasing number of arthroplasties worldwide, the number of PJI will increase correspondingly with a significant economic burden to our healthcare system. It is likely impossible to completely eradicate PJI; hence, assessment and optimization of its risk factors to preventing such a disastrous complication will be the key. There are many strategies to prevent PJI in the preoperative, intraoperative, or postoperative phases. The preoperative assessment provides a unique opportunity to screen and diagnose underlying comorbidities and optimize modifiable risk factors before elective surgeries. In this review, we will focus on current literature in preoperative assessment of various modifiable risk factors and share the experience and practical approach in our institution in preoperative optimization to reduce PJI in total joint arthroplasties.

MiR-200c promotes proliferation of papillary thyroid cancer cells via Wnt/β-catenin signaling pathway

OBJECTIVE

To investigate the potential effects of miR-200c on proliferation and apoptosis of papillary thyroid cancer (PTC) cells.

MATERIALS AND METHODS

Micro ribonucleic acid-200c (miR-200c) inhibitor was transfected to down-regulate miR-200c expression. Cell counting kit-8 (CCK-8), colony formation experiment, and flow cytometry were used to detect the effects of miR-200c knockdown on proliferation and apoptosis of Butylated Hydroxytoluene 101 (BHT101) cells. The dual-luciferase reporter gene assay was conducted to detect whether miR-200c directly binds to the target gene. After knocking down miR-200c, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting analysis were performed to detect changes of target genes regarding messenger RNA (mRNA) and protein. Western blotting analysis was also adopted to detect gene expression of Wnt/β-catenin signaling pathway-related proteins.

RESULTS

Compared with those in control group, the proliferation and clone formation ability of BHT101 cells in miR-200c knockdown group were significantly inhibited (p<0.05), while the apoptosis rate increased markedly (p<0.05). Dachshund Family Transcription Factor 1 (DACH1) was the direct target gene of miR-200c. After miR-200c knockdown, the expression levels of Wnt/β-catenin signaling pathway members (including c-Myc, β catenin and cyclin D1) all decreased.

CONCLUSIONS

MiR-200c is a tumor suppressor miRNA, which promotes proliferation of PTC cells and activates Wnt/β-catenin signaling pathway by directly regulating the corresponding target protein, DACH1.

The role of protein restriction and interaction with antibiotics in the regulation of compensatory growth in pigs: growth performance, serum hormone concentrations, and messenger RNA levels in component tissues of the endocrine growth axis

The present study investigated the effects of protein restriction and antibiotics on the hypothalamus-pituitary-liver growth axis during the compensatory growth of growing and finishing pigs. Growth performance, serum hormones, and messenger RNA (mRNA) levels of hormones and their receptors in growth axis tissues were recorded for analyses. A total of 64 piglets (large white × Landrace × Duroc cross) with an initial weight of 10.07 ± 0.14 kg were randomly divided into 4 treatment groups of 16 piglets per group. The dietary treatments consisted of 2 protein levels (14% and 20%) and 2 antibiotic levels (no antibiotics and 20 mg/kg colistin sulfate with 50 mg/kg kitasamycin) in a 2 × 2 factorial arrangement. The study was performed over 30 d for the first stage (S1, restriction phase) and 74 d for the second stage (S2, realimentation phase). The 4 treatment diets were maintained throughout the duration in the restriction phase. The 4 groups were fed the same diet in the realimentation phase. The trial period totaled 104 d. Protein restriction decreased BW, average daily food intake, and ADG in weaning pigs (P < 0.01) and induced compensatory growth after feeding a normal diet during the growth of finishing pigs. Average daily gain increased during the last phase of compensatory growth (P < 0.01). Protein restriction increased serum GH and leptin (LEP) and the mRNA levels of liver IGF-1 receptor (IGF-1-R; P < 0.01) but decreased serum IGF-1 (P < 0.01) and the mRNA levels of liver GH receptor (GH-R; P < 0.01) and IGF-1 (P < 0.05) in weaning piglets. Serum GH was increased, but serum IGF-1 was decreased during the realimentation phase (P < 0.05). Antibiotics increased the mRNA levels of GHRH (P < 0.05) and decreased somatostatin (P < 0.01) in the hypothalamus of weaning pigs. Protein restriction and antibiotics had no interactions across the entire trial. In conclusion, the slowing of growth caused by early protein restriction may be compensated for in the later stages of pig raising, and the mechanism of compensation is related to the regulation of GH, IGF-1, GH-R, and IGF-1-R.

Late gadolinium enhancement is a risk factor for major adverse cardiac events in unrecognised myocardial infarction without apparent symptoms: a meta-analysis

AIM

To assess the prognostic role of unrecognised myocardial infarction (UMI) detected at late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMRII).

MATERIALS AND METHODS

Electronic databases including PubMed, EMBASE, Medline, and Cochrane were searched systematically for studies exploring the predictive value of UMI detected by LGE-CMRI for major adverse cardiac events (MACEs) and all-cause mortality in patients without apparent symptoms. Pooled hazard ratios (HRs) along with their 95% confidence intervals (CIs) were obtained from a random-effects model. Subgroup analyses were performed according to the different participants and outcomes.

RESULTS

Eight studies (2,009 participants) were identified comprising 442 patients with UMI detected at LGE-CMRI and 1,567 without UMI. The presence of UMI on LGE was associated with a significantly increased risk for MACEs (HRs: 3.44, 95% CI: 2.06 to 5.75; p<0.001) and all-cause mortality (HRs: 2.43, 95% CI: 1.00 to 5.87; p=0.05). In the subgroup analysis, the presence of UMI on LGE remained significantly associated with the risk of MACEs in patients with suspected coronary artery disease (HRs: 3.82, 95% CI: 2.49 to 5.85; p<0.01) and diabetes mellitus (HRs: 4.97, 95% CI: 3.02 to 8.18; p<0.01).

CONCLUSION

The presence of UMI detected by LGE-CMRI is associated with an increased risk of MACEs and all-cause mortality in patients without symptoms. LGE-CMRI could provide important prognostic information and guide risk stratification in patients with UMI.

[Moderating effect of sense of coherence between occupational stress and depression]

Objective: To explore the moderating effect of sense of coherence in the relationship between occupational stress and depression. Methods: From June to September in 2018, migrant workers were purposively selected from the urban (including office buildings, shopping malls, barber shops or restaurants and other service enterprises) and suburban (including microelectronics, internet, clothing processing and art design and other factories) areas of Shanghai. A total of 3 034 people were investigated and 2 573 valid questionnaires were collected. Patient health questionnaire (PHQ), sense of coherence questionnaire (SOC) and job content questionnaire (JCQ) were used to investigate the levels depression, sense of coherence and occupational stress. Hierarchical regression analysis was used to analyze the moderating effect of sense of coherence on occupational stress and depression, and SPSS PROCESS macro program and Bootstrap method were used to further explore the moderating effect of sense of coherence. Results: The age of total 2 573 migrant workers was (28.24±7.33) years old and 49.79% of them were males. The scores of depression, occupational stress and sense of coherence were 6.67±4.74, 28.45±4.38 and 62.02±10.89, respectively. The depression level was positively correlated with occupational stress (r=0.33, P=0.007), and negatively correlated with sense of coherence (r=-0.53, P=0.003). The hierarchy regression analysis suggested that the interaction between occupational stress and sense of coherence was associated with depression symptom (β=-0.07, P=0.001). Bootstrap analysis showed that occupational stress was not associated with depression symptom with high level of sense of sense of coherence (β=0.04, 95%CI=-0.01-0.10), while occupational stress was associated with depression symptom with low level of sense of sense of coherence (β=0.19, 95%CI=0.14-0.23). Conclusion: The high level of sense of coherence has a moderating effect on the relationship between occupational stress and depressive symptoms, while the low level of sense of coherence does not have this effect.

Facilitating Phase Evolution for a High-Energy-Efficiency, Low-Cost O3-Type NaxCu0.18Fe0.3Mn0.52O2 Sodium Ion Battery Cathode

The phase transition and lattice parameter evolution of O3 structure commonly occurs in O3-type sodium ion battery (SIB) cathodes, which might enlarge the voltage hysteresis and lower the energy efficiency. Given that the cost is one of the issues discouraging the application of SIBs in large-scale energy storage, here we focus on Co/Ni-free Na_xCu_0.18Fe_0.3Mn_0.52O₂ (x = 0.8, 0.85, 0.9) and propose a convenient strategy to reduce the voltage hysteresis. It is found that when the Na content is 0.8, the highest energy efficiency of 95.4% after activation is achieved (2.5-4.0 V, 50 mA g^-1, the 50th cycle), in addition to a satisfactory capacity retention (about 0.056% decay per cycle). The further characterizations reveal that Na_0.8Cu_0.18Fe_0.3Mn_0.52O₂ owns a gentle O3-P3 phase transition process and does not undergo O3 phase lattice parameter evolution. The key point lies in the attainability of the O3/P3 composite of the material. This work will provide a simple strategy for the rational design of O3-type cathodes with a high energy efficiency and might offer inspiration to search for layered oxides with a higher O3/P3 critical Na content through element adjustments.

The investigation of hepatitis A virus and hepatitis E virus co-infection in humans and animals in China

The aim of this study was to investigate the prevalence of co-infection of hepatitis A and hepatitis E virus (HAV/HEV) in patients with acute hepatitis as well as in different animal species. A total of 46 serum samples from patients diagnosed as hepatitis A or hepatitis E and 675 fecal samples of 11 animal species were collected. The IgM class antibodies to HEV and HAV, respectively, were detected by enzyme-linked immunosorbent assay. HEV and HAV RNAs were extracted from serum and fecal samples for the nested reverse transcription polymerase chain reaction. At least 10.9% (5/46) of the patients were co-infected with both HAV and HEV. Fifteen percent (18/120) of rabbit fecal samples and 17.5% (7/40) of swine fecal samples were positive for HEV RNA, but only 1% (2/200) of ferret fecal samples were positive for HAV RNA. Our study showed that co-infection with both HAV and HEV in patients and animals is infrequent. At least in our study, we showed that ferrets may represent the potential HAV hosts. Keywords: hepatitis A virus; hepatitis E virus; co-infection; zoonosis; prevalence.

Universal haemoglobin A1c screening reveals high prevalence of dysglycaemia in patients undergoing total knee arthroplasty

INTRODUCTION

Diabetes mellitus is an established modifiable risk factor for periprosthetic joint infection (PJI). Haemoglobin A1c (HbA1c) is a glycaemic marker that correlates with diabetic complications and PJI. As diabetes and prediabetes are frequently asymptomatic, and there is increasing evidence to suggest a correlation between dysglycaemia and osteoarthritis, it is reasonable to provide HbA1c screening before total knee arthroplasty (TKA). The aim of the present study was to determine the prevalence of dysglycaemia in patients who underwent TKA and investigate whether HbA1c screening and optimisation of glycaemic control before TKA affects the incidence of PJI after TKA.

METHODS

Patients who underwent primary TKA before and after routine HbA1c screening was introduced in our unit were reviewed. Prediabetes and diabetes were defined according to the American Diabetes Association. Patients with HbA1c ≥7.5% were referred to an endocrinologist for optimisation of glycaemic control before TKA. The incidence PJI, defined according to the Musculoskeletal Infection Society criteria, was recorded.

RESULTS

A total of 729 patients (934 knees) had HbA1c screening before TKA. Of them, 17 (2.3%) and 184 (25.2%) patients had known prediabetes and diabetes, respectively, and 265 (36.4%) and 12 (1.6%) had undiagnosed prediabetes and diabetes, respectively. The incidence of PJI was significantly lower in all patients who received HbA1c screening compared with those who did not (0.2% vs 1.02%, P=0.027).

CONCLUSION

Screening for HbA1c before TKA provides a cost-effective opportunity to identify undiagnosed dysglycaemia. Patients identified as having dysglycaemia receive modified treatment, significantly reducing the rate of PJI when compared with historical controls.

Role of unfolded protein response in genital malformation/damage of male mice induced by flutamide

The unfolded protein response (UPR) is one of a switch of autophagy and apoptosis, and the endoplasmic reticulum stress (ERS) which inducing UPR plays a role in the malformations caused by some genetic and environmental factors. Exposure to flutamide during pregnancy will also cause abnormalities in some male offspring reproductive organs such as cryptorchidism. In this study, after administered the pregnant mouse orally at a dose of 300 mg/kg body weight every day during gestational day (GD)12 to GD18, flutamide can not only caused hypospadias in the male mouse offspring but also damaged the morphology and function of their testis. And the expression of UPR-related genes and proteins, autophagy, apoptosis, and angiogenesis-related genes of the damaged/teratogenic testis and penis in the mice were investigated to determine the role of UPR in this model. It was found that flutamide activated maybe the Atg7-Atg3-Lc3 pathway through the UPR pathway, caused cells excessive autophagy and apoptosis, and inhibited the formation of penile and testicular blood vessels by activating UPR and affecting the messenger RNA level of vascular endothelial growth factor and hypoxia-inducible factor 1.

Effect of phosphorus efficiency on elemental stoichiometry of two shrubs

Phosphorus (P) is an important nutrient that can restrict plant growth. However, the influence of P deficiency on elemental homeostasis and application of the growth rate hypothesis in higher plants remain to be assessed. Two shrubs, Zygophyllum xanthoxylum and Nitraria tangutorum, were used as experiment material and subjected to five P addition treatments: 0, 17.5, 35.0, 52.5 and 70.0 mg P·kg^-1 soil. The biomass and relative growth rate of Z. xanthoxylum did not change with altered P supply. There was no significant difference in P concentration among the treatments for Z. xanthoxylum, but N. tangutorum showed an upward trend. The P stoichiometric homeostasis of Z. xanthoxylum was higher than that of N. tangutorum. For Z. xanthoxylum, available P in the rhizosphere improved significantly under extreme P deficiency conditions, and P concentrations in all treatments were lower than in N. tangutorum, showing that Z. xanthoxylum had stronger P absorption and P utilization capacity. No relationships between growth rate and C:N:P ratios were found in Z. xanthoxylum. The strong P efficiency, and high and stable dry matter accumulation, are likely contributors in maintaining stoichiometric homeostasis. In addition, the relatively high biomass accumulation and high P utilization efficiency for Z. xanthoxylum does not support the growth rate hypothesis for this species.

Blood transfusions in total knee arthroplasty: a retrospective analysis of a multimodal patient blood management programme

PURPOSE

Transfusion is associated with increased perioperative morbidity and mortality in patients undergoing total knee arthroplasty (TKA). Patient blood management (PBM) is an evidence-based approach to maintain blood mass via haemoglobin maintenance, haemostasis optimisation, and blood loss minimisation. The aim of the present study was to assess the effectiveness of a multimodal PBM approach in our centre.

METHODS

This was a single-centre retrospective study of patients who underwent primary TKA in Queen Mary Hospital in Hong Kong in 2013 or 2018, using data from the Clinical Data Analysis and Reporting System and a local joint registry database. Patient demographics, preoperative haemoglobin, length of stay, readmission, mean units of transfusion, postoperative prosthetic joint infection, and mortality data were compared between groups.

RESULTS

In total, 262 and 215 patients underwent primary TKA in 2013 and 2018, respectively. The mean transfusion rate significantly decreased after PBM implementation (2013: 31.3%; 2018: 1.9%, P<0.001); length of stay after TKA also significantly decreased (2013: 14.49±8.10 days; 2018: 8.77±10.14 days, P<0.001). However, there were no statistically significant differences in readmission, early prosthetic joint infection, or 90-day mortality rates between the two groups.

CONCLUSION

Our PBM programme effectively reduced the allogeneic blood transfusion rate in patients undergoing TKA in our institution. Thus, PBM should be considered in current TKA protocols to reduce rates of transfusions and related complications.

Subpopulation targeting of pyruvate dehydrogenase and GLUT1 decouples metabolic heterogeneity during collective cancer cell invasion

Phenotypic heterogeneity exists within collectively invading packs of tumor cells, suggesting that cellular subtypes cooperate to drive invasion and metastasis. Here, we take a chemical biology approach to probe cell:cell cooperation within the collective invasion pack. These data reveal metabolic heterogeneity within invasive chains, in which leader cells preferentially utilize mitochondrial respiration and trailing follower cells rely on elevated glucose uptake. We define a pyruvate dehydrogenase (PDH) dependency in leader cells that can be therapeutically exploited with the mitochondria-targeting compound alexidine dihydrochloride. In contrast, follower cells highly express glucose transporter 1 (GLUT1), which sustains an elevated level of glucose uptake required to maintain proliferation. Co-targeting of both leader and follower cells with PDH and GLUT1 inhibitors, respectively, inhibits cell growth and collective invasion. Taken together, our work reveals metabolic heterogeneity within the lung cancer collective invasion pack and provides rationale for co-targeting PDH and GLUT1 to inhibit collective invasion.

The presence of phenotypic heterogeneity in collectively invading cells suggests cooperation amongst distinct subtypes of cells to promote invasion and metastasis. Here, the authors use chemical biology tools and report metabolic heterogeneity within the lung cancer collective invasion pack.

[Treatment of Chilomastix mesnili infection with traditional Chinese medicine: a case report]

This paper reports a case with Chilomastix mesnili infections, and summarizes the diagnosis and treatment with traditional Chinese medicine.

Early diagnostic role of PSA combined miR-155 detection in prostate cancer

OBJECTIVE

As a kind of malignant tumor in the male genitourinary system, prostate cancer exhibits significantly increased occurrence. Prostate-specific antigen (PSA) expression can be seen in the prostate cancer, prostatitis, and other diseases, therefore, lack of diagnostic specificity. The miR-155 expression is abnormally increased in the tumors. Therefore, this study aims to explore the clinical significance of PSA combined miR-155 detection in the early diagnosis of prostate cancer.

PATIENTS AND METHODS

A total of 86 patients diagnosed with prostate cancer were enrolled in this study. PSA and miR-155 gene expression in tumor tissue were detected by using Real-time PCR. The serum levels of PSA were measured by using enzyme-linked immunosorbent assay (ELISA). The correlation of PSA and miR-155 expression with age, body mass index (BMI), tumor volume, tumor-node-metastasis (TNM) stage, lymph node metastasis (LNM), and other clinicopathological features were analyzed, respectively.

RESULTS

Serum PSA expression and PSA gene in tumor tissue were significantly higher compared to that in adjacent tissues (p<0.05). PSA gene and protein increased significantly with the clinical stage of TNM and decreased following the increase of grade (p<0.05). The miR-155 level was significantly elevated in the tumor tissue compared with para-carcinoma tissue (p<0.05). PSA and miR-155 expressions were positively correlated with TNM stage, tumor volume, and LNM, and negatively correlated with grade (p<0.05).

CONCLUSIONS

PSA and miR-155 were closely related to the clinicopathological features of prostate cancer. Combined detection is helpful for the early diagnosis of prostate cancer.

Tuberculosis and diabetes in low and moderate tuberculosis incidence countries

In countries with low and moderate incidence of tuberculosis (TB), the disease tends to concentrate in specific high-risk populations such as people with diabetes mellitus (DM). We review the updated evidence on the association between 1) DM and active TB, and 2) DM and latent tuberculous infection (LTBI), and 3) we summarize the findings on the population-level impact of DM on TB epidemiology, with particular focus on low- and moderate-incidence settings. We conducted an updated review of studies on DM and active TB, and found 11 more cohort studies published after the previous systematic review from 2008. The updated pooled relative risk (RR) (2.03, 95%CI 1.62-2.55) of all the studies was substantially lower than the three-fold risk increase in the previous review. Substantial heterogeneity of RR across studies was found. Possible reasons for such heterogeneity include different levels of residual confounding, the effect of modification by age, and different levels of glycemic control in the population. In a recently published systematic review on DM and LTBI, one cohort study and 12 cross-sectional studies were identified. The results from cross-sectional studies suggest a significant but modestly increased risk of LTBI among patients with DM (pooled odds ratio 1.18, 95%CI 1.06-1.30). We reviewed evidence on the population-level impact of DM on TB epidemiology in studies using population-attributable fraction analysis and infectious disease modelling. Those studies revealed that DM accounted for a substantial TB burden in low- and moderate-incidence countries. Finally, we discussed the complex association of obesity, DM and TB risk and the impact of the global obesity pandemic on TB epidemiology.

Electron Vorticity Indicative of the Electron Diffusion Region of Magnetic Reconnection

While vorticity defined as the curl of the velocity has been broadly used in fluid and plasma physics, this quantity has been underutilized in space physics due to low time resolution observations. We report Magnetospheric Multiscale (MMS) observations of enhanced electron vorticity in the vicinity of the electron diffusion region of magnetic reconnection. On 11 July 2017 MMS traversed the magnetotail current sheet, observing tailward-to-earthward outflow reversal, current-carrying electron jets in the direction along the electron meandering motion or out-of-plane direction, agyrotropic electron distribution functions, and dissipative signatures. At the edge of the electron jets, the electron vorticity increased with magnitudes greater than the electron gyrofrequency. The out-of-plane velocity shear along distance from the current sheet leads to the enhanced vorticity. This, in turn, contributes to the magnetic field perturbations observed by MMS. These observations indicate that electron vorticity can act as a proxy for delineating the electron diffusion region of magnetic reconnection.

Interfacial Effects on the Band Edges of Ta3N5 Photoanodes in an Aqueous Environment: A Theoretical View

Ta₃N₅, as a fascinating photoanode for solar hydrogen production, is expected to split water without any bias, because its band edge potentials straddle H₂O redox potentials. Unfortunately, Ta₃N₅ photoanodes can split water only when a bias of at least 0.6–0.9 V is applied. It means that they exhibit an onset potential as high as 0.6–0.9 V_RHE (reversible hydrogen electrode). In this study, density functional theory calculations show that the band edge potentials of Ta₃N₅ have a shift of approximately −0.42 eV relative to vacuum level when exposed to water. The increased ratio of dissociated water at Ta₃N₅-water interface will further make the band edge potentials shift −0.85 eV relative to vacuum level, implying the anodic shifts of the onset potential for water oxidation. The findings may reveal the mystery of the unexpectedly high onset potential of Ta₃N₅, as high as 0.6–0.9 V_RHE.

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We have studied interfacial effects on the band edges of Ta₃N₅ in an aqueous environment

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Both water and the hydroxylated surface promote the formation of the interface dipole

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High onset potentials of Ta₃N₅ may be ascribed to negative shift of band edge potentials

Association of Fruit and Vegetable Intake and Frailty among Chinese Elders: A Cross-Sectional Study in Three Cities

OBJECTIVES

To examine the association of FVI and frailty in Chinese elders.

DESIGN

A sectional study was conducted in three cities (Shanghai, Zhengzhou, and Baoji) in China from June 2017 to June 2018.

PARTICIPANTS

A total of 5699 participants from 49 districts were included in the current study by two-stage sampling methods.

MEASUREMENTS

Frailty was measured by a validated Chinese version of the FRAIL scale. FVI per day was measured by two single questions.

RESULTS

The sample proportion with sufficient fruit intake was 36.7%, and 44.7% reported sufficient vegetable intake. The sample proportions that were robust, pre-frail, and frail were 43.6%, 38.3%, and 18.1%, respectively. Compared with low FVI, after including covariates, the odds ratio (OR) of frailty was 0.84 (95% CI: 0.73-0.97) for moderate fruit intake and 0.81 (95% CI: 0.70-0.94) for enough fruit intake; the OR of frailty was 0.83 (95% CI: 0.68-0.91) for moderate vegetable intake and 0.77 (95% CI: 0.64-0.93) for enough vegetable intake.

CONCLUSION

High FVI was negatively associated with the OR of frailty in Chinese elders. This finding implies it is important to promote FVI among adults to prevent frailty.

Responses of leaf C:N:P stoichiometry to water supply in the desert shrub Zygophyllum xanthoxylum

Based on the elemental composition of major biochemical molecules associated with different biological functions, the 'growth rate hypothesis' proposed that organisms with a higher growth rate would be coupled to lower C:N, especially lower C:P and N:P ratios. However, the applicability of the growth rate hypothesis for plants is unclear, especially for shrubs growing under different water supply. We performed an experiment with eight soil moisture levels (soil water content: 4%, 6%, 8%, 13%, 18%, 23%, 26% and 28%) to evaluate the effects of water availability on leaf C:N:P stoichiometry in the shrub Zygophyllum xanthoxylum. We found that leaves grew slowly and favored accumulation of P over C and N under both high and low water supply. Thus, leaf C:P and N:P ratios were unimodally related to soil water content, in parallel with individual leaf area and mass. As a result, there were significant positive correlations between leaf C:P and N:P with leaf growth (u). Our result that slower-growing leaves had lower C:P and N:P ratios does not support the growth rate hypothesis, which predicted a negative association of N:P ratio with growth rate, but it is consistent with recent theoretical derivations of growth-stoichiometry relations in plants, where N:P ratio is predicted to increase with increasing growth for very low growth rates, suggesting leaf growth limitation by C and N rather than P for drought and water saturation.

[Application of carbon nanoparticle in neck Ⅵ lymph node dissection for papillary thyroid carcinoma]

Objective:To investigate the application value of carbon nanoparticle lymph tracer in Ⅵ lymph node dissection for papillary thyroid cancer.Method:One hundred and forty-eight patients with papillary thyroid cancer from October 2015 to May 2016 were enrolled into the retrospective analysis. Seventy-five cases with carbon nanoparticle injected in operation were divided into observation group, while the other seventy-three cases without lymph tracer were divided into control group. The number of neck Ⅵ lymph nodes and metastatic lymph nodes between the two groups were compared, as well as the incidence of parathyroid injury and postoperative hypocalcemia. Result:There were no significant difference in age, gender, tumor size, pathology or type of operation between the two groups(P>0.05). Parathyroid injury incidence in the observation group significantly lower than the control group (5.33% vs 5.33%, P< 0.05). There was significant difference in the number of neck Ⅵ lymph node dissection between the two groups (observation group: 6.51±4.65, control group: 4.42±3.10, P< 0.05).Conclusion:Carbon nanoparticle injected as a lymph tracer in thyroid surgery is helpful, the characteristics of the parathyroid gland negative imaging can effectively decrease the rate of parathyroid gland injury.