The Flame Retardant and Mechanical Properties of the Epoxy Modified by an Efficient DOPO-Based Flame Retardant.

Currently, the mechanical performance reduction caused by excessive phosphorus content in the halogen-free flame-retardant EP has been an obstacle to its extensive application. This study presents the effective synthesis of a novel flame-retardant BDD with great efficiency, achieving an optimum phosphorus level of merely 0.25 wt %. The structure of BDD was verified by FTIR, 1H NMR, 31P NMR and XPS spectra. To investigate the flame-retardant properties of BDD, several EPs with various phosphorus levels were synthesized. The addition of phosphorus to the EP significantly increases its LOI value from 25.8% to 33.4% at a phosphorus level of 0.25 wt%. Additionally, the resin achieves a V-0 grade in the UL 94 test. The P-HRR and THR of the modified resin measured by the cone calorimeter are also significantly reduced. At the same time, the addition of a modest quantity of BDD has a minimal impact on the mechanical properties of epoxy resin. This study shows that the removal of hydroxyl groups significantly enhances the fire resistance of phosphate-based flame retardants, thereby providing a novel approach to synthesizing efficient flame retardants.

Medical Imaging Technology for Micro/Nanorobots.

Due to their enormous potential to be navigated through complex biological media or narrow capillaries, microrobots have demonstrated their potential in a variety of biomedical applications, such as assisted fertilization, targeted drug delivery, tissue repair, and regeneration. Numerous initial studies have been conducted to demonstrate the biomedical applications in test tubes and in vitro environments. Microrobots can reach human areas that are difficult to reach by existing medical devices through precise navigation. Medical imaging technology is essential for locating and tracking this small treatment machine for evaluation. This article discusses the progress of imaging in tracking the imaging of micro and nano robots in vivo and analyzes the current status of imaging technology for microrobots. The working principle and imaging parameters (temporal resolution, spatial resolution, and penetration depth) of each imaging technology are discussed in depth.

[Rapid extraction and detection of five alkaloids in dried khat by solvent extraction-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry].

Khat is a common plant that grows primarily in Eastern Africa and the Arabian Peninsula. Cathinone, norpseudoephedrine, and norephedrine are the main psychoactive components of khat. Experimental studies have shown that red and green khat have similar cathinone contents, but green khat contains more norpseudoephedrine and norephedrine than red khat. Research indicates that Ethiopians believe that red khat has stronger psychoactive effects than green khat. Therefore, we speculated that other substances in red khat may enhance its psychoactive effects. Using the sampling method, we identified two other psychoactive components in khat: methcathinone and ethcathinone. At present, only a few studies on the extraction and detection of alkaloids from khat have been published in China, and no reports on the extraction and detection of methcathinone and ethcathinone from khat are available. In this study, we established an extraction and detection method for five alkaloids in dried khat using high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF MS). To establish the extraction method, we optimized the extraction solvent and process. The amounts of dichloromethane and sodium hydroxide added during the purification step were also optimized. To establish the detection method, we optimized the chromatographic and MS conditions. The final extraction and detection method was as follows: Dried khat powder (0.1 g) was loaded into a polypropylene centrifuge tube, added with 1 mL of 0.05 mol/L hydrochloride aqueous solution, and vortex-oscillated for 3 min for extraction. The sample was centrifuged at 10000 r/min for 3 min. Next, 600 µL of the supernatant was placed in a centrifuge tube, added with 1 mL of dichloromethane, shaken for 1 min, and centrifuged at 10000 r/min for 3 min. Subsequently, 300 µL of the supernatant was placed in a centrifuge tube, added with 80 µL of 1 mol/L sodium hydroxide aqueous solution, shaken for 1 min, and added with 1 mL of acetonitrile. Vortex oscillation was performed for 2 min to extract the sample, after which solid sodium chloride (0.4 g) was added to the mixture, followed by shaking for 1 min to separate the acetonitrile and aqueous phases. The mixture was then centrifuged at 10000 r/min for 3 min. Finally, the supernatant was collected and diluted for further testing. The five target analytes were separated on a ZORBAX Eclipse Plus Phenyl-Hexyl column (100 mm×3.0 mm, 1.8 µm) via gradient elution using 0.1% acetic acid aqueous solution and acetonitrile as mobile phases with a flow rate of 0.3 mL/min and column temperature of 30 ℃. The analytes were identified using the targeted MS/MS method under positive electrospray ionization mode and quantified using the external standard method. The five alkaloids showed good correlations (all correlation coefficients (r2)≥0.9976) with their respective linear ranges. The limits of detection were between 0.08 and 0.75 µg/L, and the limits of quantification were between 0.25 and 2.50 µg/L. The average recoveries of the five alkaloids from two plants with different alkaloid contents were between 90.7% and 105.2%. The intra-sample precision ranged from 0.5% to 2.3%, the intra-day precision was between 1.0% and 2.5%, and the inter-day precision was between 1.3% and 3.3%. Using the developed method, we extracted and analyzed 15 khat samples, and detected five alkaloids. This method enables rapid sample pretreatment and has high sensitivity, good stability, and suitable accuracy. Based on the above results, we conclude that the proposed method meets the inspection and identification requirements for khat. Thus, it can provide a valuable reference for the physical and chemical identification of khat and support for further studies on its psychoactive components.

Prediction models for overall and cancer-specific survival in patients with metastatic early-onset colorectal cancer: a population-based study.

PURPOSE: Metastatic early-onset colorectal cancer (EO-CRC) is on the rise, yet there is a dearth of predictive models for this disease. Therefore, it is crucial to develop a nomogram to aid in the early detection and management of metastatic colorectal cancer in young patients. METHODS: We retrieved data from the SEER database on patients with metastatic colorectal cancer aged 50 or younger between 2010 and 2017. The data were randomly allocated in a 7:3 ratio to training and validation cohorts, and univariate and multivariate Cox regression analyses were used to identify independent prognostic factors for overall survival (OS) and cancer-specific survival (CSS) at 1, 3, and 5 years. The nomograms were developed based on these factors, and their discriminatory and calibration capabilities were validated. Using the nomogram risk scores, patients were stratified into low-risk and high-risk groups. RESULTS: The study included 2470 patients with metastatic EO-CRC. Univariate and multivariate Cox regression analysis identified 12 independent risk factors that were included in the nomogram. The training cohort had a consistency index (C-index) of 0.71, while the validation cohort had a C-index of 0.70, demonstrating good predictive accuracy. Calibration plots showed a high level of consistency between the observed and predicted values, with overlapping plots along the diagonal. The decision curve analysis (DCA) revealed that the nomogram had a high clinical application value. CONCLUSIONS: The novel nomograms were created to predict the prognosis of patients with metastatic EO-CRC, which can aid clinicians in developing more effective treatment strategies and contribute to more accurate prognostic assessments.

Analysis of DAT Combined with the VSD Technique in Wound Repair of Rats and Its Effect on Inflammatory Factors.

The clinical efficacy of decellularized adipose tissue (DAT) combined with vacuum sealing drainage (VSD) in the treatment of wound healing in rats is investigated, and the changes of inflammatory factors are analyzed. The tissue defect model of SD (Sprague-Dawley) rats is established and divided into the combined group (n = 12) and the control group (n = 12) according to different treatment methods. The control group is treated with a single VSD technique, and the combined group is treated with DAT on the basis of the control group. The wound healing time of the two groups is observed. Wound tissue is collected 1 day, 10 days, 20 days, and 30 days after treatment, and neutrophil infiltration is observed by HE (hematoxylin-eosin) staining. The expression changes of IL-6 and IL-13 at each time point before and after treatment are compared. Histological observation shows that the cell infiltration is reduced in both groups, and the wound repair in the combined group is better than that in the control group. The experimental results show that the DAT combined with the VSD technique can further speed up wound healing and reduce inflammation in rats.

Messenger effects in COVID-19 communication: Does the level of government matter?

Public efforts to limit the spread of the coronavirus rely on motivating people to cooperate with the government. We test the effectiveness of different governmental messengers to encourage preventive health actions. We administered a survey experiment among a sample (n = 1,545) of respondents across the United States, presenting them with the same social media message, but experimentally varying the government sender (i.e., Federal, State, County, a combination of Federal + County, and a control condition) to test whether local relevance influences messaging efficacy. We find that in an information saturated environment the messenger does not matter. There is, however, variation in treatment response by partisanship, education, income, and the degree to which respondents are affected by the pandemic. While the main effect of the level of government on intended behavior is null, public health organizations are universally perceived as more trustworthy, relevant, and competent than anonymous messengers.

Divided Eyelid Nevus: Surgical Repair Discussion and Case Reports From Northwestern China.

Currently, due to the lack of long-term postoperative follow-up outcomes of the congenital divided eyelid nevus, we described our surgical approaches and presented the functional and cosmetic results of 13 patients with an average of 5-year follow-up. Based on the surgical treatments and the follow-ups, the selection of total or subtotal excision depends on the lesion location and the use of blepharoplasty approaches is determined by defect size. The CO2 laser may be a useful second-stage procedure to ablate remnant lesions, but long-term monitoring is required.

Étant donné le peu de suivi postopératoire à long terme sur les résultats cliniques de la réparation du nævus palpébral congénital en miroir, les chercheurs décrivent les méthodes chirurgicales utilisées et présentent les résultats fonctionnels et esthétiques chez 13 patients, suivis sur une période moyenne de cinq ans. D'après les traitements chirurgicaux et les suivis, le choix d'une excision totale ou partielle dépend du foyer de la lésion, et le mode de blépharoplastie repose sur la dimension de l'anomalie. Le laser CO2 peut être utilisé en deuxième phase pour faire disparaître les vestiges des lésions, mais une surveillance à long terme s'impose.

Establishment of a predictive model for outcomes in patients with severe acute pancreatitis by nucleated red blood cells combined with Charlson complication index and APACHE II score.

BACKGROUND/AIMS: Nucleated red blood cell (NRBC) is an immature red blood cell, which can appear in the peripheral blood of newborns but not in normal adults. However, in the presence of hemorrhage, severe hypoxia, or severe infection, NRBCs may exist in adult blood and are associated with prognosis. The aims of this study were to establish a predictive model for the outcome of patients with severe acute pancreatitis (SAP) based on NRBCs. MATERIALS AND METHODS: Data from 92 patients with SAP were retrospectively collected for the study. We used chi-square automatic interaction detection (CHAID) to explore a prediction model of mortality in patients with SAP by NRBCs. RESULTS: During the 90-day follow-up, 11 participants (12.0%) died. The NRBC-positive rate of nonsurvivors was much higher than survivors (90.9% vs. 23.5%). Charlson Comorbidity Index (CCI), Acute Physiology and Chronic Health Evaluation II (APACHE II), Ranson score, and serum C-reactive protein were higher in nonsurvivors (5.0, 29.0, 6.0, and 140.0 g/L) than survivors (3.0, 13.0, 4.0, and 54.7 g/L). A CHAID model including NRBC, CCI, APACHE II score, and Ranson score showed that NRBCs differentiated well between nonsurvivors and survivors. All patients with SAP survived when they had a negative test result for NRBCs and CCI was below 7. All patients died when they had a positive test result for NRBCs and APACHE II score exceeded 30. Among patients whose NRBC test result was positive and APACHE II score was below 30, if the Ranson score was less than 5, the mortality rate was only 5.6%, whereas the mortality rate was 66.7% if the Ranson score exceeded 5. A validated population of 32 patients showed that the accuracy of the prediction model was 100%. CONCLUSION: NRBC combined with CCI, APACHE II, and Ranson score can predict 90-day mortality of patients with SAP.

[Opportune time and method of reconstruction of penile defects caused by devastating electrical burn].

OBJECTIVE: To explore the timing and suitable method of reconstructing penile defects caused by devastating electrical burn. METHODS: Thirteen patients with penile defects after devastating electrical burn, hospitalized from September 1998 to August 2013, were included in this study. After the necrotic tissues in the wounds were removed by dressing changes, a local or a hinge-like flap constructed from scrotum or abdominal wall, a prelaminated hinge-like flap from forearm, or a free forearm flap was selected, according to the injury degree of the penis, for the repair of the defect or reconstruction of penis respectively. RESULTS: The flaps survived and the wounds healed well in 2 patients repaired with local flaps from scrotum or abdominal wall. Urethritis occurred in 2 patients 6 to 9 months after the transplantation of hinge-like flaps from scrotum, and they were cured by appropriate drugs. Functions of urination and erection of penis were recovered in these 4 patients. All flaps survived in the 5 patients repaired with hinge-like flaps from abdominal wall or prelaminated flaps from forearm. The wounds in 2 patients healed; wound dehiscence occurred in the other 3 patients in different degrees, and they healed after suturing for 2 or 3 times. The function of erection of penis recovered in these 5 patients, but with discontinuity of urinary stream during urination. Among them, 3 married patients enjoyed satisfactory sexual life. All free forearm flaps survived and the wounds healed well in 4 patients. Urinary fistula occurred in 1 patient, and it was repaired by a secondary operation. These 4 patients experienced normal urination function, but only 2 patients in whom corpus spongiosum partially remained retained the function of erection of penis to certain degree. All these 4 patients could not perform normal sexual intercourse. All patients were followed up for 6 to 13 months after surgery. Under ordinary state, the length of penis was 5.9-9.3 cm, and the circumference of penis was 8.4-10.0 cm. Wound scar was not obvious in all cases. Nine patients reported a restricted erection. CONCLUSIONS: Penile defect caused by devastating electrical burn should be repaired with a suitable flap after necrotic tissues are removed with dressing change. To repair affected penis with necrosis of a small part of cavernous body and/or corpus spongiosum, or combined with urethra defects, local flaps from scrotum or abdominal wall or hinge-like flap from scrotum should be employed. To repair those with necrosis of a large part or the whole of corpus spongiosum combined with urethra defects, hinge-like skin flaps from abdominal wall or prelaminated flaps from forearm should be employed. In patients with necrosis of a large part of cavernous body and corpus spongiosum combined with urethra defect, or total loss of penis, free forearm flaps should be employed to reconstruct penis.