Biocompatible Janus microparticle synthesis in a microfluidic device.

Janus particles are popular in recent years due to their anisotropic physical and chemical properties. Even though there are several established synthesis methods for Janus particles, microfluidics-based methods are convenient and reliable due to low reagent consumption, monodispersity of the resultant particles and efficient control over reaction conditions. In this work a simple droplet-based microfluidic technique is utilized to synthesize magnetically anisotropic TiO2-Fe2O3 Janus microparticles. Two droplets containing reagents for Janus particle were merged by using an asymmetric device such that the resulting droplet contained the constituents within its two hemispheres distinct from each other. The synthesized Janus particles were observed under the optical microscope and the scanning electron microscope. Moreover, a detailed in vitro characterization of these particles was completed, and it was shown that these particles have a potential use for biomedical applications.

Biosensor for ATP detection via aptamer-modified PDA@POSS nanoparticles synthesized in a microfluidic reactor.

This study introduces aptamer-functionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticles for adenosine triphosphate (ATP) detection where the POSS nanoparticles were synthesized in a one-step, continuous flow microfluidic reactor utilizing thermal polymerization. A microemulsion containing POSS monomers was generated in the microfluidic reactor which was designed to prevent clogging by using a continuous oil flow around the emulsion during thermal polymerization. Surfaces of POSS nanoparticles were biomimetically modified by polydopamine. The aptamer sequence for ATP was successfully attached to POSS nanoparticles. The aptamer-modified POSS nanoparticles were tested for affinity-based biosensor applications using ATP as a model molecule. The nanoparticles were able to capture ATP molecules successfully with an affinity constant of 46.5 [Formula: see text]M. Based on this result, it was shown, for the first time, that microfluidic synthesis of POSS nanoparticles can be utilized in designing aptamer-functionalized nanosystems for biosensor applications. The integration of POSS in biosensing technologies not only exemplifies the versatility and efficacy of these nanoparticles but also marks a significant contribution to the field of biorecognition and sample preparation.

Synthesis of Anisotropic Magnetic Polymeric Janus Particles by In Situ Separation of Magnetic Nanoparticles in a Microfluidic Device.

Magnetic Janus particles have been studied extensively for medical and biological applications owing to their controllable mobility in fluid media. In this work, we report a novel microfluidic device designed for the synthesis of magnetically anisotropic Janus particles made of poly(ethylene glycol) diacrylate and embedded with magnetic iron oxide nanoparticles. Our method consists of a droplet generation step followed by magnetic separation using an external magnetic field and ultraviolet polymerization. The synthesized particles exhibit a monodisperse size distribution with a standard deviation of less than 3.5%, which is among the best size distributions obtained in the literature for magnetic Janus particles. The anisotropic magnetic property of the particles enable them to rotate about their own axes in the presence of an external magnetic field, introducing another degree of freedom to their motion. This microfluidic technique is simple, one-step, and versatile, offering control over the size distribution to synthesize magnetically anisotropic Janus particles.

The effect of climatic and seasonal factors on the microbial keratitis profile.

PURPOSE: To compare retrospective data on microbial keratitis (MK) from two different climatic regions in Turkey over 11 years. STUDY DESIGN: Retrospective cohort. METHODS: This retrospective cohort study included patients diagnosed with presumed MK at two referral centers. Center A was located in the subtropical region of Turkey, whereas Center B was located in a continental temperate climate zone. Clinical and laboratory data were also recorded. The results were evaluated for seasonal variations. RESULTS: This study included data from 665 patients with presumed MK (351 and 314 patients from centers A and B, respectively). The most common predisposing factors were ocular trauma in Center A, prior ocular surgery, and systemic disease in Center B. Severe keratitis was related to prior ocular surgery, presence of systemic disease, and fungal infection at presentation. The culture positivity rate was higher in spring and lower in summer at both centers. Gram-positive bacteria were the most commonly isolated bacteria in both centers in all seasons. The fungal and mixed keratitis ratios were higher in Center A than in Center B. In Center A, filamentous fungi were common pathogens that were found year-round, and peaks were observed in July and October. CONCLUSION: The results of this study show that climatic and seasonal factors may affect the microbial profile of keratitis. Fungal keratitis appears to be a climatic disease. Understanding the regional profile of MK can aid clinicians in their disease management.

The effect of preemptive magnesium sulfate on postoperative pain in patients undergoing mastectomy: a clinical trial.

OBJECTIVE: The effects of preemptive magnesium sulfate (MgSO4) infusion on perioperative hemodynamics and postoperative analgesia in female patients who underwent mastectomy were evaluated. PATIENTS AND METHODS: American Society of Anesthesiologists (ASA) I-II female patients aged 18 years and over who underwent mastectomy were randomized into 2 groups, including 34 individuals each. The study group (Group I) was given 50 mg/kg MgSO4 in 250 ml isotonic 30 minutes before the induction, and the control group (Group II) was given 250 ml of normal isotonic solution. Standardized anesthesia was applied. Perioperative oxygen saturation, mean arterial pressure (MAP), pulse (HR), sedation scores (ss) in the recovery unit, Verbal Numeric Rating Scale (VNRS), need for rescuer fentanyl, and analgesic needs in the surgical period were evaluated. RESULTS: Demographic variables were similar. There was no statistical difference between the two groups in terms of the MAP, HR, and oxygen saturation values measured at entry, post-intubation, 15th, 30th, 45th, 60th minutes, and after extubation. There was a statistically significant difference between the two groups in terms of VNRS scores in the recovery unit and at the 2nd, 4th, 8th, and 12th hours during the postoperative surgical period (p=0.0001, 0.001, 0.001, 0.004, 0.021, respectively). The need for rescue analgesics in the first 2 hours of recovery was found to be lower in the study group (p=0.005). The need for postoperative analgesics in the surgical period was not statistically significant (p=0.1). CONCLUSIONS: Preemptive use of MgSO4 reduces postoperative VNRS scores without affecting hemodynamic parameters during induction and maintenance of general anesthesia.

Antibacterial properties and osteoblast interactions of microfluidically synthesized chitosan - SPION composite nanoparticles.

In this research, a multi-step microfluidic reactor was used to fabricate chitosan - superparamagnetic iron oxide composite nanoparticles (Ch - SPIONs), where composite formation using chitosan was aimed to provide antibacterial property and nanoparticle stability for magnetic resonance imaging (MRI). Monodispersed Ch - SPIONs had an average particle size of 8.8 ± 1.2 nm with a magnetization value of 32.0 emu/g. Ch - SPIONs could be used as an MRI contrast agent by shortening T2 relaxation parameter of the surrounding environment, as measured on a 3 T MRI scanner. In addition, Ch - SPIONs with concentrations less than 1 g/L promoted bone cell (osteoblast) viability up to 7 days of culture in vitro in the presence of 0.4 T external static magnetic field. These nanoparticles were also tested against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), which are dangerous pathogens that cause infection in tissues and biomedical devices. Upon interaction of Ch - SPIONs with S. aureus and P. aeruginosa at 0.01 g/L concentration, nearly a 2-fold reduction in the number of colonies was observed for both bacteria strains at 48 h of culture. Results cumulatively showed that Ch - SPIONs were potential candidates as a cytocompatible and antibacterial agent that can be targeted to biofilm and imaged using an MRI.

Microfluidic Methods in Janus Particle Synthesis.

Janus particles have been at the center of attention over the years due to their asymmetric nature that makes them superior in many ways to conventional monophase particles. Several techniques have been reported for the synthesis of Janus particles; however, microfluidic-based techniques are by far the most popular due to their versatility, rapid prototyping, low reagent consumption and superior control over reaction conditions. In this review, we will go through microfluidic-based Janus particle synthesis techniques and highlight how recent advances have led to complex functionalities being imparted to the Janus particles.

The frequency of osteoporosis in patients with predialysis chronic renal failure and the factors affecting the development of osteoporosis.

BACKGROUND: Osteoporosis is a common public health problem in chronic kidney patients. The risk factors for osteoporosis in patients with nondialysis CKD have not been fully investigated. It is not known exactly whether the risk factors of osteoporosis in the general population are also valid for the nondialysis CKD patients. Aims: This study aims to determine the frequency of osteoporosis and the risk factors for osteoporosis in nondialysis CKD patients. PATIENTS AND METHODS: Our study was performed with 283 nondialysis stage 3-5 CKD patients. According to the BMD results, the patients were classified into groups as normal, osteopenia and osteoporosis according to World Health Organization criteria. Monocyte/high-density lipoprotein-cholesterol ratio (MHR), neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) were calculated individually for all cases. RESULTS: According to our BMD results, 67 (24%) patients were found to have osteoporosis. In the osteoporosis patient group, compared to the normal BMD group, females were higher and the mean age was higher (P = 0.025, P = 0.028). Body mass index (BMI) and eGFR were lower in the osteoporosis group (P = 0.013). Parathyroid Hormone and Platelet-to-lymphocyte ratio in the patients in the osteoporosis group was higher than of those in the normal group (P = 0.026, P = 0.035). In the multivariate logistic regression analysis, advanced age, female gender, and low BMI were determined as independent risk factors for the development of osteoporosis in nondialysis CKD patients. CONCLUSION: Advanced age, female gender and low BMI are the risk factors for osteoporosis in nondialysis CKD patients. It may be a rational approach to measure BMD for the diagnosis of osteoporosis in nondialysis CKD patients who are elderly, female and have low BMI.

The smartphone addiction, peer relationships and loneliness in adolescents.

This descriptive study was carried out to examine the relationship between smartphone addiction, peer relationships, and loneliness in adolescents. The sample consisted of 500 adolescents aged between 15-18 years, who were high school students in Central Anatolia region during the 2018-2019 academic year. The data of the study was collected through a questionnaire, Smartphone Addiction Scale-Short Version (SAS-SV), Friendship Qualities Scale (FQS) and UCLA Loneliness Scale (ULS). Statistical analyses included descriptive statistics, Shapiro-Wilk, and Spearman correlation test. The SAS-SV, FQS and ULS mean scores were 27.82±11.53, 81.88±15.68, and 41.99±8.62, respectively. Results indicated there was a weak positive correlation between the companionship subscales of both FQS and ULS with SAS-SV. There was a weak negative correlation between the conflict subscales of FQS and SAS-SV. Providing a special education to adolescents and their parents to raise their awareness on the negative effects of smartphone addiction may be recommended.

Randomised controlled study of seroma rates after mastectomy with and without quilting the skin flap to pectoralis muscle.

AIMS: The aim of this study was to determine whether seroma formation was affected by reduction of the potential dead space with the flap fixation method and obliteration of the axillary region in patients with breast cancer who underwent either mastectomy and axillary lymph node dissection or sentinel lymph node biopsy. A total of 105 patients with breast cancer were divided into two groups according to wound closure patterns. PATIENTS AND METHODS: The operating time, postoperative pain and complications, time to drain removal, seroma formation, amount of fluid aspirated and number of aspirations were recorded prospectively. RESULTS: No significant difference was found between groups in the rates of seroma development (P = 0.7), complication rates (P = 0.6), time to drain removal (P = 0.5), length of hospital stay (P = 0.3) or numbers of aspiration (P = 0.7). The operating time for fixation was determined to be longer than that of the classic procedure (P = 0.02). CONCLUSIONS: Reducing potential dead space with flap fixation and obliteration of the axillary region may be useful in decreasing the development of seroma in patients who have undergone mastectomy because of breast cancer. However, surgical technique must be careful, and appropriate patient follow-up must be conducted.

Describing Droplet Motion on Surface-Textured Ratchet Tracks with an Inverted Double Pendulum Model.

We describe the motion of a droplet on a textured ratchet track using a nonlinear resonator model. A textured ratchet track is composed of a semicircular pillar array that induces a net surface tension local gradient on a droplet placed on it. When a vertical vibration is applied, hysteresis is overcome, and the droplet moves toward the local lower energy barrier; however, due to the repetitive structure of texture, it keeps moving until the end of the track. The droplet motion depends on the amplitude and frequency of the vertical oscillation, and this dependence is nonlinear. Therefore, finding a fully analytic solution to represent this motion is not trivial. Consequently, the droplet motion remains poorly understood. In this study, we elaborate on the utility of a double pendulum as a basis for modeling the droplet motion on surfaces inducing asymmetric force. Similar to the droplet motion, resonators, such as a double pendulum, are simple, yet nonlinear systems. Moreover, an inverted double pendulum motion has key characteristics such as the two-phase motion and the double peak motion, which are also observed in the droplet motion. We use various data-processing methods to highlight the similarity between these two systems both qualitatively and quantitatively. After establishing this comparison, we propose a model that utilizes an inverted double pendulum mounted on a moving cart to successfully simulate the motion of a droplet on a ratchet track. This methodology will lead to the development of an accurate droplet-motion modeling approach, and we believe that it will be useful to understand droplet dynamics more deeply.

Textured surfaces as a new platform for nanoparticle synthesis.

We present a new, surface-based microfluidic platform for the synthesis of nanoparticles. In this platform chemical reagents are carried in separate droplets, then mixed and later transported to a desired location on the surface using surface textured ratchet tracks. This brings the advantages of both synthesizing and transporting nanoparticles in situ without having cross-contamination between samples and addressing each sample independently. This platform is also capable of carrying multiple synthesis reactions concurrently.

Alternating Droplet Formation by using Tapered Channel Geometry.

The ability to produce a controlled sequence of alternating droplets from two separate sources inside a microfluidic system brings several advantages in microfluidic analysis. The effectiveness of this technique for use in an application depends on the ability of the device to replicate the pattern continuously and accurately. In this work we studied the effect of the dispersed phase channel geometry on generating a repeating pattern of alternating droplets in a cross junction microfluidic device. By measuring the radius of curvature of a droplet at the time of break up, and calculating the Laplace pressure using these values, we analyzed how the angle of taper of the dispersed phase inlet channel has an influence on the pattern repetition and uniformity of formed droplet size and spacing in between. The performance of devices with different angle of taper values were studied experimentally. This comparative study indicated that the ability of a cross junction device to generate alternating droplets with uniform size and spacing is highly dependent on the angle of taper of the inlet channels; and it improves with larger taper angles.

Outcome of ICSI with motile testicular spermatozoa obtained through microscopically assisted testicular sperm extraction in relation to the ovarian response.

INTRODUCTION: To determine the relationship between AFC, basal FSH level, woman's age, the number of oocytes retrieved and the outcome of ICSI with testicular spermatozoa obtained with microscopically assisted testicular sperm extraction. MATERIAL AND METHODS: In this retrospective cohort study, a total of 340 couples who underwent ICSI treatment with testicular sperm were enrolled. Women aged?40years and the first cycles of couples were included. ICSI was performed with motile testicular spermatozoa obtained from 89 men with obstructive azoospermia and 251 men with nonobstructive azoospermia. GnRH-antagonist protocol was used for ovulation induction. Simple linear regression was carried out to analyze relationship between the AFC, basal FSH, woman's age, the number of oocytes, and the live birth rate (LBR). Receiver operator characteristic curves (ROC) were formed to detect cut-off values below which LBR was significantly decreased. ROC curve analysis demonstrated that the cut-off level of the number of oocytes retrieved to predict the LBR was 7. According to this cut-off level, all patients were divided into two groups. Women with retrieved<7 oocytes were included in Group 1 and women with retrieved?7 oocytes were included in Group 2. RESULTS: The mean age of men was 35.1±4.9years. The mean age, mean FSH level and mean AFC of women were 32.1±4.9years, 6.9±2.7 IU/L, 7.6±3.4, respectively. Significant correlations were found between AFC, the number of oocytes retrieved, and the LBR per ICSI cycle with testicular spermatozoa. The LBR was significantly lower in women with AFC<8 than those with AFC?8. Independently, the LBR was significantly lower in cycles with<7 oocytes retrieved compared to those with ?7. Embryo transfer was not achieved in 37 cycles with<7 oocytes (37/167, 22.1%) and 18 cycles with?7 (18/173, 10.4%) because of the absence of transfer-quality embryos (P=0.005). The LBRs were the lowest in cycles with one or two oocytes available (8.3 and 8.3%, respectively), but these rates were not statistically different than those in cycles with 3, 4, 5 and 6 oocytes (14.2, 17.2, 18.5, 17.6%, respectively, P=0.810). CONCLUSIONS: AFC and the number of oocytes retrieved are important prognostic factors in an ICSI cycle with testicular sperm in women ?40years, yielding significantly diminished LBRs with<8 antral follicles and/or<7 oocytes retrieved.

Management of upper and lower molars that are displaced into the neighbouring spaces.

Our aim was to describe our experience of retrieval of accidental displacements of upper and lower molars into neighbouring anatomical spaces. Thirteen patients were evaluated retrospectively in terms of age, sex, affected side, jaw (mandible or maxilla), surgeon's experience, whether the extracted teeth had erupted, which portion of the tooth or teeth was displaced, the anatomical space into which the fragment was displaced, postoperative complaints, timing of the retrieval, type of anaesthesia, and surgical approach. There were no significant differences in sex, affected side, which part of the tooth was displaced, whether the extracted teeth had erupted, type of anaesthesia, or timing of retrieval. We conclude that this condition should be treated, although follow-up alone may be an option. The intraoral lingual pouch approach for complications of mandibular third molars and the intraoral Caldwell-Luc operation for those in the maxilla could be successful options for retrieval.

SPARCS and Pelli-Robson contrast sensitivity testing in normal controls and patients with cataract.

PurposeTo determine the ability of the newly developed internet-based Spaeth/Richman Contrast Sensitivity (SPARCS) test to assess contrast sensitivity centrally and peripherally in cataract subjects and controls, in comparison with the Pelli-Robson (PR) test.MethodsIn this prospective cross-sectional study, cataract subjects and age-matched normal controls were evaluated using the SPARCS and PR tests. Contrast sensitivity testing was performed in each eye twice in a standardized testing environment in randomized order. SPARCS scores were obtained for central, right upper (RUQ), right lower (RLQ), left upper (LUQ), and left lower quadrants (LLQ). PR scores were obtained for central contrast sensitivity. PR and SPARCS scores in cataract subjects were compared with controls. Intraclass correlation coefficients (ICC) and Bland Altman analysis were used to determine test-retest reliability and correlation.ResultsA total of 162 eyes from 84 subjects were analyzed: 43 eyes from 23 cataract subjects, and 119 eyes from 61 controls. The mean scores for SPARCS centrally were 13.4 and 14.5 in the cataract and control groups, respectively (P=0.001). PR mean scores were 1.31 and 1.45 in cataract and control groups, respectively (P<0.001). ICC values for test-retest reliability for cataract subjects were 0.75 for PR and 0.61 for the SPARCS total. There was acceptable agreement between the ability of PR and SPARCS to detect the effect of cataract on central contrast sensitivity.ConclusionsBoth SPARCS and PR demonstrate a significant influence of cataract on contrast sensitivity. SPARCS offers the advantage of determining contrast sensitivity peripherally and centrally, without being influenced by literacy.

A microwave molecular solution based approach towards high-κ-tantalum(V)oxide nanoparticles: synthesis, dielectric properties and electron paramagnetic resonance spectroscopic studies of their defect chemistry.

Stable dispersions of tantalum oxide nanoparticles are accessible from solutions of tantalum(V) complexes with a mixed malonato and alkanolato ligand sphere in ethoxyethanol by microwave processing. The malonato ligand is cleaved during decomposition and acetic acid or acetic acid esters are formed as derived from in situ spectroscopic studies. The solubility of the tantalum precursor and the obtained particle size therefrom depend strongly on the type of alkanolato ligand moiety. Dispersions of the molecular complexes possess good film forming properties. Films with low surface roughness can be obtained by spincoating. These exhibited a dielectric constant of about 15 and disruptive strengths above 1.5 MV cm(-1). The electrical measurements indicate that the presence of moisture is detrimental with respect to the dielectric performance of the films. After removal of the solvent from the suspensions of the nanoparticles, the residue can be redispersed in aprotic solvents. The particles can be isolated therefrom by precipitation with pentane. XRD and HRTEM indicate that the material remains amorphous up to temperatures of 750 °C. XPS proved that only Ta2O5 is formed as lower oxidation states of Ta cannot be detected. A detailed EPR study allows us to gain insight into the surface defect chemistry. Multiple types of oxygen vacancies exist at the surface of the Ta2O5 particles which are influenced by additional calcination and annealing in a vacuum.

Production performance, use of nest box, and external appearance of two strains of laying hens kept in conventional and enriched cages.

The aim of this study was to investigate the differences in production performance, use of nest box, and external appearance of 2 strains of laying hens kept in conventional and enriched cages. Lohmann Brown Classic (LB, n=532) and Lohmann LSL Classic (LW, n=532) hens were housed from 16 to 73 wk in either conventional cages or enriched cages. Enriched cages had a nesting area, scratch pad, perch, and nail shortener. Body weight (BW), hen-day egg production, egg weight, feed intake, feed conversion ratio (FCR), cracked and dirty eggs, use of nest box for lay, and external appearance were determined. Laying period influenced the hen-day egg production, egg weight, feed intake, and feed conversion ratio. Cage type affected the hen-day egg production and feed conversion ratio, while strain affected the egg weight, feed intake, and feed conversion ratio. Laying period×cage type and laying period×strain interactions affected egg production, egg weight, and feed conversion ratio. Both strains preferred to lay in the nest box. Percentages of cracked and dirty eggs of LW hens in enriched cages were higher than that in conventional cages. Most of the dirty eggs laid by both strains were found outside of the nest box. The LW hens laid more dirty eggs than the LB hens. Cage type and cage type×strain interaction were important for total feather score. Final claw length was affected by cage type, strain, and cage type×strain interaction. This study suggests that cage type, strain, and also cage type×strain and period×strain interactions should be considered when alternative housing systems are used.

Effects of breeder age on mineral contents and weight of yolk sac, embryo development, and hatchability in Pekin ducks.

The current study was carried out to investigate the effects of breeder age on egg composition, changes of embryo, yolk sac, and yolk minerals during incubation and hatchability in Pekin ducks. A total of 495 freshly laid eggs were obtained from the same flock of Pekin ducks, aged 28, 34, and 40 wk, and were reared in accordance with the management guide of the duck breeders (Star 53-Grimaud Freres). At each breeder age, egg measurements were made on a random subsample of unincubated eggs. Embryo and yolk sac measurements were made on embryonic day (E) 12, E16, E20, and E25. On d 28 of incubation, the healthy ducklings were removed and sex of chicks was determined. All chicks were weighed and hatching results were determined. Egg weight and yolk percentages increased; however, albumen percentages, shell thickness, and yolk index decreased as the flock aged. Shell percentages, shell breaking strength, albumen index, and haugh units were not affected by breeder age. Also, breeder age affected the Mg, P, K, Ca, Cu, and Zn levels in the yolk, except for Na level on day of setting, and breeder age affected the mineral consumed by embryo during incubation. However, on E25, the levels of examined minerals, except for P level in the yolk sac, were not statistically different in duck breeder age groups. Relative yolk sac and embryo weights of eggs obtained from different breeder ages varied from E16 to E25; however, embryo length was different in breeder age groups from E12 to E20. Hatching weight was affected by breeder age and sex. Hatching results were not different among breeder age groups. This study indicates that breeder age is important for some egg characteristics, relative yolk sac weight, some contents of minerals in the yolk, embryonic growth during incubation, and duckling weight.