Droplet Evaporation Process of a Fluorobenzene + n-Octane + Polystyrene Mixture.

The vapor-liquid equilibrium of the fluorobenzene-polystyrene binary polymer solution at 303.15 K was measured using a static pressure device. The vapor-liquid equilibrium of the fluorobenzene-n-octane-polystyrene ternary solution in a partial concentration range under normal pressure was determined using an improved Othmer equilibrium still, in which the octane concentration was low. Three activity coefficient models, poly-NRTL, UNIQUAC, and M-UNIQUAC-LBY, were utilized to correlate the experimental data of binary and ternary solutions, and the component activities of the fluorobenzene-n-octane-polystyrene solution at 303.15 K were predicted. A mathematical model based on the Stefan flow was developed to simulate the evaporation process of composite spherical droplets. The activity predicted by the activity coefficient model was used for numerical simulations, and compared with simulations using the activity following Raoult's law. The comparative analysis revealed that simulations based on Raoult's law and activity coefficient models yielded similar results when the mass fraction of fluorobenzene exceeded 0.6. However, in the later stages of evaporation, the calculations based on Raoult's law predicted a 10% shorter drying time for fluorobenzene. The activity coefficient models provided a better approximation and exhibited similar droplet diameter shrinking behaviors to the actual evaporation process.

Targeted gene disruption by CRISPR/xCas9 system in Drosophila melanogaster.

Although the Cas9 protein from Streptococcus pyogenes (SpCas9) is the most widely used clustered regularly interspaced short palindromic repeats (CRISPR) variant in genome engineering experiments, it does have certain limitations. First, the stringent requirement for the protospacer adjacent motif (PAM) sequence limits the target DNA that can be manipulated using this method in insects. Second, its complementarity specifications are not very stringent, meaning that it can sometimes cause off-target effects at the target site. A recent study reported that an evolved SpCas9 variant, xCas9(3.7), with preference for various 5'-NG-3' PAM sequences not only has the broadest PAM compatibility but also has much greater DNA specificity and lower genome-wide off-target activity than SpCas9 in mammalian cells. Here we applied the CRISPR/xCas9 system to target the white gene in Drosophila melanogaster, testing the genome-editing efficiency of xCas9 at different PAM sites. On the GGG PAM site, xCas9 showed less activity than SpCas9. For the non-NGG PAM site TGA, xCas9 could produce DNA cleavage and indel-mediated disruption on the target gene. However, for other non-NGG PAM sites, xCas9 showed no activity. These findings show that the evolved Cas9 variant with broad PAM compatibility is functional in Drosophila to induce heritable gene alterations, increasing the targeting range for the applications of genome editing in insects.

The effect of borneol on the concentration of meropenem in rat brain and blood.

Meropenem is a carbapenem antibiotic with a wide spectrum of activity against both Gram-positive and Gram-negative bacteria. Because of its clinical efficacy, meropenem is an excellent choice for the treatment of serious infections in both adults and children. The knowledge of tissue concentrations of antibiotic in an infection site is valuable for the prediction of treatment outcome. The aim of the present study is to investigate the effect of borneol on the concentration of meropenem in rat brain and blood and to find the potential relationships of the combined use of medicine and traditional Chinese medicine. Analysis of meropenem in the dialysates was achieved using the microdialysis technique and HPLC. At 40 min after the administration of an intraperitoneal injection of meropenem, the concentration of meropenem in brain in borneol+meropenem group was 2.25 (0.35) µg ml(-1), which was significantly higher than that in meropenem group [1.20 (0.12) µg ml(-1); P < 0.01]. Within 80 min of drug administration, the AUCbrain/AUCblood (area under the curve, AUC) in the borneol+meropenem group was 1.2 times that of the meropenem group. Borneol can increase the concentration of meropenem in the cerebrospinal fluid, but has no influence on its blood concentration. This study represents a successful application of the microdialysis technique, which is an effective method for the study of pharmacokinetics of meropenem.

An insecticide target in mechanoreceptor neurons.

Hundreds of neurotoxic insecticides are currently in use. However, only a few direct targets have been identified. Here, using Drosophila and the insecticide flonicamid, we identified nicotinamidase (Naam) as a previous unidentified molecular target for an insecticide. Naam is expressed in chordotonal stretch-receptor neurons, and inhibition of Naam by a metabolite of flonicamid, TFNA-AM (4-trifluoromethylnicotinamide), induces accumulation of substrate nicotinamide and greatly inhibits negative geotaxis. Engineered flies harboring a point mutation in the active site show insecticide resistance and defects in gravity sensing. Bees are resistant to flonicamid because of a gene duplication, resulting in the generation of a TFNA-AM-insensitive Naam. Our results, in combination with the absence of genes encoding Naam in vertebrate genomes, suggest that TFNA-AM and potential species-specific Naam inhibitors could be developed as novel insecticides, anthelmintics, and antimicrobials for agriculture and human health.

Application of MPR in sacral nerve injury during sacral fracture.

BACKGROUND: To investigate the diagnostic and clinical value of multiplanar reconstruction (MPR) with spiral computed tomography for sacral nerve injury during sacral fracture. METHODS: From April 2007 to April 2009, 10 patients with sacral nerve injury during sacral fracture admitted to the Affiliated Shenjing Hospital of China Medical University were included in this study; of these, seven were men and three were women, aged around 30 years to 55 years. Hospital admission time from injury was around 1 day to 30 days for these patients. Causes of injury included six cases of car crashes, three cases of fallen heavy objects, and one case of crush injury. To evaluate fracture status of the sacral neuroforamen and relative position of fractured bone to the root of nerve, entire neuroforamen of sacral nerve was observed by MPR technique at double-oblique position (45-degree oblique coronary position and 30-degree oblique sagittal position), under which the fracture condition of sacral neuroforamen could be clearly displayed for further clinical verification. RESULTS: According to the 1990 standard classification for spinal injury by the National Spinal Cord Injury Association and the International Spinal Cord Society, with consideration of the clinical manifestations, clinical diagnosis of all patients were as follows: six cases of injury to S1 root, two cases of injury to S2 root, two cases of injury to both S1 and S2 roots, three cases of penetration of S1 neuroforamen by fractured bone after MPR at double-oblique position, one case of injury to S2 neuroforamen, and two cases of penetration of both S1 and S2 neuroforamen by fractured bone. Diagnosis of last six patients was confirmed by surgery (observed compression of S1 and S2 nerves by fractured bones). In addition, after removal of compression causes, symptoms of the patients were significantly improved, and patients completely recovered in an average of 12 weeks. After the MPR examination at double-oblique position, the remaining four patients (3 cases of injury to S1 and 1 case of injury to S2) did not show penetration of fractured bones to neuroforamen (thus considering the diagnosis of simple neural contusion). These patients recovered well after an average of 13-week conservative therapy. CONCLUSION: Sacral MPR at double-oblique position can be used as a routine examination for patient with sacral fracture, which is of great significance in determining the cause of injury to sacral nerve. Furthermore, it can also provide radiologic evidences to analyze the need for surgical therapy.

[Significance of double-oblique multiplanar reconstruction of the treatment decision-making in sacral fracture with sacral neurological damage].

OBJECTIVE: To study diagnostic and surgical significance of the multiplanar reconstruction (MPR) of spiral CT in sacral fracture with sacral neurological damage. METHODS: From April 2007 to April 2009, 10 cases of sacral fracture with sacral neurological damage in Shengjing Hospital of China Medical University were examined by double-oblique MPR of sacrum to show a total length of the sacral neural tube, and observe the course of sacral neural tube and the relationship between fracture and the neural tube. There were 7 males and 3 females, aged 30 - 55 years. The time from injury to hospitalization varied from 1 day to 1 months. The injury was caused by traffic accident in 6 cases, smash of heavy object in 3 cases and crush in 1 cases. All patients were examined with double-oblique MPR (coronal oblique 45 degrees and 30 degrees oblique-shaped bit lost)to display the course of sacral neural tube and the condition of clearly, which was confirmed by operation and clinical validation. RESULTS: The clinical manifestations and international standards for Neurological Classification of Spinal Cord Injury recommended by American Spinal Injury Association International Spinal Cord Society were the basis for clinical diagnose. Nerve injury diagnosed by clinical manifestation were S1 (6 cases), S2 (2 cases), S1 and S2 (2 cases). After double-oblique MPR in patients, we found 3 patients have fractures in sacral neural tube of S1, 1 patients in S2, and 2 patients both in S1 and S2, whom recovered average 12 month after operation (S1 and S2 nerve were pressed by fractures according to operating observation); And there were no fractures in sacral neural tube of other patients (3 cases in S1, 1 cases in S2), these were contund, whom were recovered average 13 month after expectant treatment. CONCLUSIONS: Double-oblique MPR of sacrum has important clinical significance in diagnosis of nature and location with sacral nerve injury, as well as surgical planning. It can be used as routine examination of patients with sacral fracture.

The effect of intra-articular injection of antibacterial drugs in the clinical treatment of prosthetic joint infection in patients undergoing artificial hip replacement.

OBJECTIVE: To study the clinical effect of intra-articular injection of antimicrobials in the treatment of prosthetic joint infection (PJI) in patients undergoing artificial hip replacement surgery and its impact on the quality of life. METHODS: A retrospective analysis of the clinical data of 116 patients with PJI after artificial hip replacement in our hospital from June 2016 to June 2017 was performed, and they were randomly divided into a study group and a control group, with 58 in each group. The study group was treated with intra-articular injection of antibacterial drugs, and the control group was injected with sodium hyaluronate. The antibacterial effects of the two groups were compared. RESULTS: The HHS scores of the two groups of patients after treatment increased (P < 0.001), and the increase of the study group was more relevant (P < 0.001). The IL-17 and IL-6 levels noticeably decreased (P < 0.001), and the decrease in the study group was more significant (P < 0.001). The total effective rate after 6 weeks of treatment in the study group was evidently higher compared with the control group (P < 0.05). The quality of life scores of the two groups of patients after treatment increased (P < 0.001), and the the study group was much better (P < 0.001). Lower incidence of adverse reactions was identified in the study group (P < 0.05). CONCLUSION: Intra-articular injection of antimicrobials can effectively improve the hip joint function of patients, reduce inflammation, improve the quality of life, and the incidence of adverse reactions is relatively low. It has high clinical application value and is worthy of use and promotion.

[Experimental expression of HIF-1α in rabbit adipose-derived mesenchymal stem cells by dynamic compression plus IGF-1 gene transfection].

OBJECTIVE: To investigate the effects on HIF-1α expression of rabbit adipose-derived mesenchymal stem cells (ADSCs) by dynamic compression plus IGF-1 gene transfection and explore the mechanism of promoting chondrogenesis by HIF-1α. METHODS: The ADSCs were harvested after the digestion of typeIcollagenase and transfection with pcDNA3.1-IGF-1. And then the cells were seeded onto chitosan/gelatin scaffolds with a density of 5 × 10(7) cells/ml and divided into groups: Group A (control), non-transfected ADSCs; Group B (IGF-1), hIGF-1 gene transfected ADSCs; Group C (loading), untransfected ADSCs with stimulation of compressive loading; Group D (loading + IGF-1), hIGF-1 gene transfected ADSCs and loading stimulation. The dynamic compression was carried out with a bio-reactor at a frequency of 0.1 Hz and a sinusoidal strain amplitude of 2% (2% at 0.1 Hz). The dynamic load was performed every 20 minutes, 4 hours daily. After 7 days, morphological observation was performed. The MTT assay was used to detect the cell proliferation. Meanwhile the CM-DiI cell-labeling solution was used to observe the distribution of cells. The total amount of GAG and the expression of related genes of IGF-1, HIF-1α, type II collagen (COL II) and Sox-9 were quantified. RESULTS: The best morphology was found in loading+ IGF-1 group. The results of proliferating capacity were: Group A < C < B < D (P < 0.01); Dil fluorescence showed that the cells were well-distributed in Group D. Meanwhile, the content of total GAG and the expression of related genes demonstrated: Group A < C < B < D (P < 0.01). And the combined effect was more significant than either alone. CONCLUSION: In three-dimensional culture conditions, dynamic compression plus IGF-1 transfection can significantly enhance the level of autocrine IGF-1. Both of two experimental intervention factors can significantly up-regulate the mRNA level of HIF-1α. And they exert a synergistic effect. HIF-1α plays an important role in promoting the chondrogenesis and the synthesis and secretion of extra-cellular matrix.

Curcumin Regulates the Progression of Colorectal Cancer via LncRNA NBR2/AMPK Pathway.

OBJECTIVE: To identify the effect of curcumin on tumor suppression and the possible molecular pathways involved. METHODS: The expression of long noncoding RNA neighbor of BRCA1 lncRNA 2 (NBR2) was quantified using reverse transcription-polymerase chain reaction on cultured colorectal cancer cells. Next, we used Western blot to measure the activation of adenosine monophosphate-activated protein kinase and mechanistic target of rapamycin kinase (mTOR) signaling molecules. Both cell proliferation and viability were measured via MTT assay, and the cell ratio and S phase were detected by BrdU assay. Colorectal cancer cells were pretreated with curcumin or transfected with shNBR2 or adenosine monophosphate-activated protein kinase inhibitor Compound C to examine the molecular pathway involved. RESULTS: Current data showed that glucose deficiency increased the expression of NBR2 in colorectal cancer cells, and NBR2 knockdown affected the progression of colorectal cancer cells under glucose starvation conditions. When NBR2 was silenced in the treated colorectal cancer cells, the proliferation, the clone formation, and the percentage of S-phase cells suppressed by glucose deprivation were compromised. Furthermore, NBR2 knockdown could suppress glucose deprivation-induced adenosine monophosphate-activated protein kinase activation plus mTOR inactivation. Similarly, when colorectal cancer cells were treated with curcumin, the expression of NBR2 was significantly increased. NBR2 knockdown reversed curcumin-suppressed proliferation, clone formation, and the percentage of S-phase colorectal cancer cells. Furthermore, NBR2 knockdown abolished curcumin-induced activation of adenosine monophosphate-activated protein kinase and inactivation of the mTOR signaling pathway. CONCLUSION: This study revealed a novel mechanism by which long noncoding RNA NBR2 mediates curcumin suppression of colorectal cancer proliferation by activating adenosine monophosphate-activated protein kinase and inactivating the mTOR signaling pathway.

[Distribution characteristics and risk factors of colorectal adenomas].

OBJECTIVE: To determine the detection rate and distribution characteristics of colorectal adenomas in Ningbo area of China, and to identify the risk factors for colorectal adenoma, in order to provide reference for colorectal cancer screening. METHODS: A cross-sectional study was performed among 8660 subjects undergoing colonoscopy in the Ningbo No.2 Hospital between January and December 2016, using a questionnaire, including demographic data (age, gender, height and weight), history of diseases (diabetes, hypertension, hyperlipidemia, and family history of malignant neoplasm), lifestyle (smoking, alcohol, dietary bias on red meat, dietary bias on fruit and vegetables, dietary frequency of pickled food and physical activities), and intestinal early warning symptoms. All colonoscopically detected polyps were removed for histological examination. Polyps were histologically divided into non-adenomatous (hyperplastic polyps and inflammatory polyps) and adenomatous polyps (tubular, villous, tubulovillous and serrated adenomas). Pathologic features were analyzed according to anatomical site. Multivariate logistic regression analysis was used to identify the risk factors for colorectal adenoma. RESULTS: A total of 7077 subjects who received colonoscopic examination and completed the questionnaire survey were enrolled in this study. There were 3633 males and 3444 females with a median age of 53 (ranged 17 to 83) years. Adenoma detection rate was 15.6% (1103/7077) in all cases, 21.0%(762/3633) for males, and 9.9%(341/3444) for females(P=0.000). Detection rate of 6.2%(29/469) was recorded in individuals aged less than 30 years, 8.0%(87/1086) in those from 30 to 39 years, 12.1%(148/1222) in those from 40 to 49 years, 16.8%(272/1623) in those from 50 to 59 years, 20.4%(326/1601) in those from 60 to 69 years, and 22.4%(241/1076) in those ≥70 years. The detection rate increased according to age(P=0.000). A total of 1521 adenomas were detected in 1103 cases, including 1455 tubular adenomas, 33 tubulovillous adenomas, 9 villous adenomas and 24 serrated adenomas. Among 1521 adenomas, 44.1%(n=671) located in the right hemicolon, 39.0%(n=593) in the left hemicolon, and 16.9%(n=257) in the rectum. Significantly larger number of serrated adenomas and advanced adenomas (advanced adenoma was defined as any adenoma with high-grade intraepithelial neoplasia, diameter ≥10 mm or with villous component) was observed in the right hemicolon compared to left hemicolon and rectum [serrated adenomas: 2.5%(17/671) vs. 0.8% (5/593) and 0.8% (2/257), P=0.029; advanced adenoma: 9.2% (62/671) vs. 5.2% (31/953) and 6.6% (17/257), P=0.021]. Multivariate analysis showed that malely (P=0.003), elderly (P=0.000), obesity (P=0.014), smoking (P=0.001), alcohol (P=0.032), and family history of malignancy (P=0.000) were independent risk factors of colorectal adenoma. CONCLUSIONS: In view of a higher detection rate of colorectal adenoma in population aged 40 to 49 years especially in male individuals, the starting age of colonoscopy screening may be advanced to 40 years old. People with family history of malignancy, obesity, and habit of smoking or drinking should be regarded as important subjects for colonoscopy screening. During colonoscopy screening, special emphasis should be given to right hemicolon.

[Study on bone mesenchymal stem cells transfected by polyethylene glycol/bone morphogenetic protein-2].

OBJECTIVE: Polyethylene glycol/bone morphogenetic protein-2 (PEG/BMP-2) nanoparticles were transfected into Rabbit bone mesenchymal stem cells (rBMSCs) and the expression of BMP-2 was detected. METHODS: Dissociated rBMSCs were primarily cultured in vitro and BMP-2 gene was transfected into rBMSCs by PEG/BMP-2 nanoparticals and lipofectamine, respectively. The efficiency of transfection was detected by flow cytometry and the expression of BMP-2 was detected by Western Blot and real time RT-PCR. RESULTS: PEG/BMP-2 nanoparticals were successfully synthesized and transfected into rBMSCs. Compared with the lipofectamine transfection group, PEG/BMP-2 transfection group had higher efficiency and higher BMP-2 expression. CONCLUSION: PEG/BMP-2 nanoparticals transfected rBMSCs highly expressed BMP-2,which provided novel strategies for the treatment of bone defect.

Dynamic compression promotes proliferation and neovascular networks of endothelial progenitor cells in demineralized bone matrix scaffold seed.

Neovascularization is required for bone formation and successful fracture healing. In the process of neovascularization, endothelial progenitor cells (EPCs) play an important role and finish vascular repair through reendothelialization to promote successful fracture healing. In this study, we found that dynamic compression can promote the proliferation and capillary-like tube formation of EPCs in the demineralized bone matrix (DBM) scaffold seed. EPCs isolated from the bone marrow of rats have been cultured in DBM scaffolds before dynamic compression and then seeded in the DBM scaffolds under dynamic conditions. The cells/scaffold constructs were subjected to cyclic compression with 5% strain and at 1 Hz for 4 h/day for 7 consecutive days. By using MTT and real-time PCR, we found that dynamic compression can significantly induce the proliferation of EPCs in three-dimensional culture with an even distribution of cells onto DBM scaffolds. Both in vitro and in vivo, the tube formation assays in the scaffolds showed that the loaded EPCs formed significant tube-like structures. These findings suggest that dynamic compression promoted the vasculogenic activities of EPCs seeded in the scaffolds, which would benefit large bone defect tissue engineering.