Risk assessment and clinical prediction model of planned transfer to the ICU after hip arthroplasty in elderly individuals.

BACKGROUND: With the development of hip arthroplasty technology and rapid rehabilitation theory, the number of hip arthroplasties in elderly individuals is gradually increasing, and their satisfaction with surgery is also gradually improving. However, for elderly individuals, many basic diseases, poor nutritional status, the probability of surgery, anaesthesia and postoperative complications cannot be ignored. How to reduce the incidence of postoperative complications, optimize medical examination for elderly patients, and reasonably allocate medical resources. This study focuses on the construction of a clinical prediction model for planned transfer to the ICU after hip arthroplasty in elderly individuals. METHODS: We retrospectively analysed 325 elderly patients who underwent hip arthroplasty. The general data and preoperative laboratory test results of the patients were collected. Univariate and multivariate logistic regression analyses were performed to screen independent influencing factors. The backwards LR method was used to establish the prediction model. Then, we assessed and verified the degree of discrimination, calibration and clinical usefulness of the model. Finally, the prediction model was rendered in the form of a nomogram. RESULTS: Age, blood glucose, direct bilirubin, glutamic-pyruvic transaminase, serum albumin, prothrombin time and haemoglobin were independent influencing factors of planned transfer to the ICU after hip arthroplasty. The area under the curve (AUC) of discrimination and the 500 bootstrap internal validation AUC of this prediction model was 0.793. The calibration curve fluctuated around the ideal curve and had no obvious deviation from the ideal curve. When the prediction probability was 12%-80%, the clinical decision curve was above two extreme lines. The discrimination, calibration and clinical applicability of this prediction model were good. The clinical prediction model was compared with the seven factors in the model for discrimination and clinical use. The discrimination and clinical practicability of this prediction model were superior to those of the internal factors. CONCLUSION: The prediction model has good clinical prediction ability and clinical practicability. The model is presented in the form of a linear graph, which provides an effective reference for the individual risk assessment of patients.

Effect of Cold Working on the Properties and Microstructure of Cu-3.5 wt% Ti Alloy.

Cu-Ti alloys were strengthened by ß'-Cu4Ti metastable precipitation during aging. With the extension of the aging time, the ß'-Cu4Ti metastable phase transformed into the equilibrium ß-Cu4Ti phase. The Cu-3.5 wt% Ti(Cu-4.6 at% Ti) alloys with different processing were aged at different temperatures for various times after solution treatment at 880 °C for 1 h. The electrical conductivity of samples under different heat treatments had shown an upward trend as time increased during aging, but the hardness reached the peak value and then decreased. The hardness and electrical conductivity of the samples with 70% deformation after aging are higher tha n the samples without deformation. Deformation after aging would cause the metastable phase to dissolve into a matrix. The best combination value of conductivity and hardness is 13.88% IACS and 340.78 Hv, and the optimal heat treatment is 500 °C for 2 h + 70% deformation + 450 °C for 2 h.

A Novel System for the Quantification of the ADCC Activity of Therapeutic Antibodies.

Novel ADCC effector cells expressing the V-variant or F-variant of FcγRIIIa (CD16a) and firefly luciferase under the control of a chimeric promoter incorporating recognition sequences for the principal transcription factors involved in FcγRIIIa signal transduction, together with novel target cells overexpressing a constant high level of the specific antigen recognized by rituximab, trastuzumab, cetuximab, infliximab, adalimumab, or etanercept, confer improved sensitivity, specificity, and dynamic range in an ADCC assay relative to effector cells expressing a NFAT-regulated reporter gene and wild-type target cells. The effector cells also contain a normalization gene rendering ADCC assays independent of cell number or serum matrix effects. The novel effector and target cells in a frozen thaw-and-use format exhibit low vial-to-vial and lot-to-lot variation in their performance characteristics reflected by CVs of 10% or less. Homologous control target cells in which the specific target gene has been invalidated by genome editing providing an ideal control and a means of correcting for nonspecific effects were observed with certain samples of human serum. The novel effector cells and target cells expressing noncleavable membrane-bound TNFα have been used to quantify ADCC activity in serum from patients with Crohn's disease treated with infliximab and to relate ADCC activity to drug levels.

The influence of metal ions on the dielectric enhancement and radical generation of rice starch during microwave processing.

In this study, the effect of the enrichment of rice starch with metal ions on its capability to generate free radicals during microwave processing was investigated. The underlying mechanism was explored from two aspects: dielectric and thermal properties. Rice starch was modified with ions of iron, copper, manganese and calcium. The modified starches were analyzed in terms of dielectric properties, activation energy (Ea) and thermodynamic characteristics of gelatinization. The quantity and character of the free radicals were analyzed using electron paramagnetic resonance (EPR). The results showed that the metal ions could change the dielectric property and inter structure of rice starch, thus influencing the ability of rice starch to generate radicals under microwave irradiation.

[Prevalence of central sleep apnea in different age groups of children with sleep apnea-hypopnea].

OBJECTIVE: To explore the prevalence of central sleep apnea in different age groups of children with sleep apnea-hypopnea (SAH). METHODS: A total of 431 children with SAH diagnosed by overnight polysomnography at our Sleep Center were retrospectively studied. They were divided into 3 groups based on their ages: toddler group (1 - < 3 years old), preschool group (3 - < 6 years old) and school group (6 - < 13 years old). The relationship between age and different types of apnea-hyponea index (AHI) was analyzed. And the prevalence of central sleep apnea and sleep structure were compared between the groups. RESULTS: A negative correlation existed between age and central sleep apnea index (r = -0.322, P < 0.01). However, there was no correlation between age and obstructive apnea index (P > 0.05). AHI was similar in different age groups, but the medians of central sleep apnea index for toddler, preschool and school groups were 2.35, 1.50 and 0.90 events/h respectively (all P < 0.01). Sleep structure was similar between the groups (P > 0.05). CONCLUSIONS: Central sleep apnea is common in children with sleep disordered breathing. The younger their ages, a higher prevalence of central sleep apnea.

Mitochondria associate with P-bodies and modulate microRNA-mediated RNA interference.

P-bodies are cytoplasmic granules that are linked to mRNA decay, mRNA storage, and RNA interference (RNAi). They are known to interact with stress granules in stressed cells, and with late endosomes. Here, we report that P-bodies also interact with mitochondria, as previously described for P-body-related granules in germ cells. The interaction is dynamic, as a large majority of P-bodies contacts mitochondria at least once within a 3-min interval, and for about 18 s. This association requires an intact microtubule network. The depletion of P-bodies does not seem to affect mitochondria, nor the mitochondrial activity to be required for their contacts with P-bodies. However, inactivation of mitochondria leads to a strong decrease of miRNA-mediated RNAi efficiency, and to a lesser extent of siRNA-mediated RNAi. The defect occurs during the assembly of active RISC and is associated with a specific delocalization of endogeneous Ago2 from P-bodies. Our study reveals the possible involvement of RNAi defect in pathologies involving mitochondrial deficiencies.

Study of the optimisation of puffing characteristics of potato cubes by spouted bed drying enhanced with microwave.

BACKGROUND: In commercial deep-fat frying of potato chips, the oil content of the final products ranges from 35 to 45 g 100 g(-1) (wet basis). High-temperature frying may cause the formation of acrylamide, making the products unhealthy to the consumer. The aim of this research was to explore a new method, spouted bed microwave drying, to produce healthier puffed snack potato cubes as possible alternatives to oil-fried potato chips. The influence of drying conditions of the spouted bed microwave drying on puffing characteristics of potato cubes were studied and compared with the direct microwave and hot air drying method. RESULTS: Tandem combination drying of microwave-enhanced spouted bed drying (MWSB) could achieve a good expansion ratio, breaking force and rehydration ratio. The puffing characteristics of potato cubes were significantly affected (P < 0.05) by moisture content before starting microwave power in spouted bed microwave drying, by microwave (MW) power, and by the original size of potato cubes. CONCLUSION: The optimum processing parameters were the moisture content at the start of microwave power (60%), the size of potato cubes (10-12 mm), and microwave power (2-2.5 W g(-1))

[Effect of human cytomegalovirus on hematopoietic system].

OBJECTIVE: To investigate the mechanism and the suppression effect of human cytomegalovirus (HCMV) on hematopoietic system. METHODS: Semi-solid culture system was used to observe the effect of HCMV AD169 strain on colony forming unit granulocyte/macrophage (CFU-GM), CFU-erythroid (CFU-E), CFU-multipotent (CFU-Mix) and CFU-megakaryocyte (CFU-MK) growth. The techniques of in situ polymerase chain reaction (IS-PCR) and polymerase chain reaction (PCR) were used to demonstrate the existence of HCMV DNA in the colony cells of cultured CFU-GM, CFU-Mix, CFU-MK and CFU-E, respectively. The immediate early antigen (IEA) mRNA in CFU-MK and late antigen (LA) mRNA in CFU-E were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). HCMV early protein P52 was detected with immunohistochemical technique. RESULTS: HCMV AD169 suppressed the differentiation and proliferation of CFU-GM, CFU-E, CFU-Mix and CFU-MK in vitro significantly (P < 0.05). The suppression was dose-dependent. HCMV DNA was successfully detected in CFU-GM, CFU-Mix, CFU-MK colony cells from viral infection groups by IS-PCR, and was detected in CFU-E by PCR, while it was negative in blank control or mock control groups. CFU-MK colony cells expressed HCMV IEA mRNA with the size of 340 bp in virus infection groups of 10(3) plague forming unit (PFU), 10(4) PFU and 10(5) PFU, respectively. The HCMV LA mRNA was detected by RT-PCR and was 263 bp long in positive control group of HCMV-infected human embryonic fibroblasts. The expression of HCMV LA mRNA in CFU-E was negative. The early protein P52 of HCMV in 10(4) PFU group was also identified by immunohistochemical staining. CONCLUSION: HCMV AD169 strains inhibited the differentiation and proliferation of CFU-GM, CFU-E, CFU-Mix and CFU-MK by the infection of the hematopoietic progenitors. HCMV might cause the suppression of hematopoiesis by direct infection, which is thought to be one of the reasons of HCMV infection associated with thrombocytopenia, neutropenia and anemia.