Formulation development of tazarotene-loaded PLGA nanoparticles for follicular delivery in the treatment of inflammatory skin diseases.

Tazarotene is a widely prescribed topical retinoid for acne vulgaris and plaque psoriasis and is associated with skin irritation, dryness, flaking, and photosensitivity. In vitro permeation of tazarotene was studied across the dermatomed human and full-thickness porcine skin. The conversion of tazarotene to the active form tazarotenic acid was studied in various skin models. Tazarotene-loaded PLGA nanoparticles were prepared using the nanoprecipitation technique to target skin and hair follicles effectively. The effect of formulation and processing variables on nanoparticle properties, such as particle size and drug loading, was investigated. The optimized nanoparticle batches with particle size <500 µm were characterized further for FT-IR analysis, which indicated no interactions between tazarotene and PLGA. Scanning electron microscopy analysis showed uniform, spherical, and non-agglomerated nanoparticles. In vitro release study using a dialysis membrane indicated a sustained release of 40-70 % for different batches over 36 h, following a diffusion-based release mechanism based on the Higuchi model. In vitro permeation testing (IVPT) in full-thickness porcine skin showed significantly enhanced follicular and skin delivery from nanoparticles compared to solution. The presence of tazarotenic acid in the skin from tazarotene nanoparticles indicated the effectiveness of nanoparticle formulations in retaining bioconversion ability and targeting follicular delivery.

Statistical Study Concerning Extraction and Non-Extraction Methods in Orthodontic Treatments.

INTRODUCTION: The need to extract permanent teeth for the correction of dento-maxillary anomalies remains even today a controversy in orthodontic therapy. The purpose of this study was to assess the orthodontist's point of view on the extraction and non-extraction methods used in orthodontic treatments, regarding clinical experience. MATERIAL AND METHODS: A de novo conceived questionnaire was elaborated by means of Google Forms and it comprised 22 questions regarding gender, age, different proprieties and aspects of both extraction and non-extraction methods and the percentage of treated patients who developed an increase in dental sensitivity and caries activity following the therapeutic stripping procedure. RESULTS: 204 orthodontists answered the questionnaire. The respondents chose dental stripping (IPR-interproximal reduction) as the most used non-extraction method in their orthodontic practice with 34,3%, followed by over-expansion and dental stripping 24%. The probability that females will try to avoid dental extractions is 1.888 times higher compared to males. The association is statistically significant (p-value 0.0336). 70,1% of clinicians state that they use dental stripping as a non-extraction method to gain space even when there is NO Bolton discrepancy. In Class III cases, for reducing crowding and correcting the dental relations, 65.2% of doctors opt for dental stripping, while 34.8% do not avoid the extraction of a lower incisor. CONCLUSIONS: Among the non-extraction methods for creating space, the most used by the surveyed orthodontists was dental stripping IPR. Tooth extraction remains a solution used by orthodontists for treating dentomaxillary disharmonies with crowding.

High-Performance Dendrite-Free Lithium Metal Anode Based on Metal-Organic Framework Glass.

The performance of lithium metal batteries is severely hampered by uncontrollable dendrite growth and volume change within the anode. This work addresses these obstacles by introducing a novel strategy: applying an isotropic and internal grain-boundary-free layer, specifically, a metal-organic framework (MOF) glass layer with nano-porosity onto the electrochemically plated lithium metal anode. Both ab initio and classical molecular dynamics simulations indicate that the MOF glass layer makes the lithium transport smooth and uniform via its internal monolithic and interfacial advantages. This MOF glass layer with the fast and more uniform lithium diffusion in the monolithic interior and its interface enables dendrite-free lithium plating and stripping through surface confinement effect and interfacial effect. When employed in symmetric batteries, the achieved Li metal anode can operate over 300 h at 1 mA cm-2. The full batteries matched with LiFePO4 exhibit high capacity (148 mAh g-1), excellent rate performance (61 mAh g-1 at 5 C), and outstanding cycling stability (with capacity retention of ≈90% after 1000 cycles). The full batteries matched with high-voltage LiCoO2 also show superior performances. Therefore, the strategy of utilizing a MOF glass layer enables the development of high-performance lithium metal anodes.

Transforming waste cellulosic fabric dyed with Reactive Yellow C4GL into value textile by a microwave assisted energy efficient system of color stripping.

A million ton of cotton fabric is wasted during cutting process in garment industry as well as in textile dyeing industry due to faulty dyeing. Color stripping of cotton fabric has become a significant challenge in the textile industry because the harsh chemicals used in chemical stripping processes affects the quality of fabric very badly. Conventional stripping methods lead with severe effects due to prolonged treatment time and high chemical concentrations. Recently, microwave-assisted stripping techniques have been emerged as effective alternatives to improve stripping efficiency. In this research, the developed microwave assisted stripping system is improved by the application of Urea, which is utilized as a microwave absorber to further reduce stripping time, temperature, and chemical concentration kept focus on quality parameters of recycled cotton fabric. This study inspects the efficiency of microwave absorber-assisted alkali hydrolysis and reduction in terms of dye-fabric bond cleavage, chromophores removal, chemical consumption, and processing time and compared with sequential stripping, microwave assisted stripping without absorber and conventional methods. The results indicated that microwave absorber-assisted alkali hydrolysis and reduction achieved 90 % stripping efficiency by using lowest concentrations of chemicals, while sequential stripping yielded a stripping efficiency of 96 %. Similarly, microwave absorber assisted methods resulted in minor loss in tear strength and weight. These outputs highlight the superior performance of microwave absorber-assisted techniques, demonstrating their efficiency, novelty, time-saving nature, and reduced damage compared to other methods.

A Detailed Analysis of Individuals Having Graft Failure After Corneal Transplantation.

PURPOSE: To describe demographic and clinical characteristics of patients with graft failure after keratoplasty, determine the cause of graft failure and outcomes. METHODS: The charts of patients between 2008-2013 in the Cornea Service at Wills Eye Hospital with a history of a corneal transplant before the end of 2012 were retrospectively reviewed. Included were patients who had graft failure after corneal transplantation and had at least one year of follow-up after transplantation. Penetrating keratoplasty (PK) and Descemet's stripping endothelial keratoplasty (DSEK) patients were analyzed separately. RESULTS: A total of 186 eyes of 170 patients with graft failure after a PK (156) or DSEK (30) procedures were identified. The baseline characteristics included 100 female and 70 male patients with an age between 0 and 90 years (median 63 years). At the time of surgery, 38% had three or more systemic diseases and 68% were using three or more systemic medicines. Mean follow up time for PK was nearly four times of DSEK. Only 2 DSEK eyes (7%) underwent a 3rd DSEK graft, while 47 (30%) PK eyes underwent a 3rd PK and 15 (10%) PK eyes underwent more than three PK procedures. CONCLUSIONS: Most DSEK failures occurred in 1st year, while graft failure in PKs is scattered over years. Failure in DSEK is mostly due to graft or surgical risk factors but in PK mostly due to factors in the host. DSEK does not appear to be as affected by the patients' demographic and clinical characteristics as much as PK.

Transmembrane Chemical Absorption Process for Recovering Ammonia as an Organic Fertilizer Using Citric Acid as the Trapping Solution.

Membrane contactors are among the available technologies that allow a reduction in the amount of ammoniacal nitrogen released into the environment through a process called transmembrane chemical absorption (TMCA). This process can be operated with different substances acting as trapping solutions; however, strong inorganic acids have been studied the most. The purpose of this study was to demonstrate, at laboratory scale, the performance of citric acid as a capturing solution in TMCA processes for recovering ammonia as an organic fertilizer from anaerobic digestor reject water using membrane contactors in a liquid-liquid configuration and to compare it with the most studied solution, sulfuric acid. The experiments were carried out at 22 °C and 40 °C and with a feed water pH of 10 and 10.5. When the system was operated at pH 10, the rates of recovered ammonia from the feed solution obtained with citric acid were 10.7-16.5 percentage points (pp) lower compared to sulfuric acid, and at pH 10.5, the difference decreased to 5-10 pp. Under all tested conditions, the water vapor transport in the system was lower when using citric acid as the trapping solution, and at pH 10 and 40 °C, it was 5.7 times lower. When estimating the operational costs for scaling up the system, citric acid appears to be a better option than sulfuric acid as a trapping solution, but in both cases, the process was not profitable under the studied conditions.

EndoVenous-assisted invaginated stripping of the great saphenous vein: A pilot and feasibility study.

Objective: By incorporating an endovascular component into Great Saphenous Vein stripping, EndoVenous-assisted Invaginated Stripping (EVIS) aims to make the procedure minimally invasive. A study was conducted to investigate the surgical intervention. Methods: Sketches and videos were used to illustrate the technical aspects of EVIS. A prospective cohort study included 20 patients with chronic venous insufficiency (CVI). Results: EVIS is performed as a day-surgery. Technical success was 100%, and no complications were recorded. The mean operative time was 45 minutes, intraoperative pain score was 4.8, post-operative pain was 2.5, 1.8, 1.2, 0.5 at 48 hours, 1, 4, and 12 weeks, respectively. The mean blood loss was 15 mL, and the mean length of the GSV strapped was 19 cm. The follow-up duplex showed a reduction in the diameter of the residual GSV stump. Conclusions: EVIS is a combination of standard techniques that may prove valuable in managing CVI.

Synthesis and application of bismuth nanoparticle-loaded longan porous carbon for simultaneous electrochemical determination of Pb(II) and cd(II) in seafoods.

The discarded longan shell-derived porous carbon material (LPC) served as a scaffold for synthesizing bismuth nanoparticle-loaded longan porous carbon nanocomposite (BiNPs@LPC) via a hydrothermal method. Then BiNPs@LPC was utilized to modify screen-printed carbon electrodes (SPCE) for simultaneous detection of Pb(II) and Cd(II) by square wave anodic stripping voltammetry (SWASV). The material was thoroughly characterized by scanning electron microscopy, X-ray diffraction, Raman spectra, Brunauer-Emmett-Teller analysis, electrochemical impedance spectroscopy and cyclic voltammetry. BiNPs@LPC exhibited abundant porous structures, high surface area, and numerous active sites, which could improve significantly response sensitivity. Under optimal conditions, the peak currents of Pb(II) and Cd(II) exhibited favorable linear relationships with the concentration within a range of 0.1-150 µg L-1, with detection limits (S/N = 3) of 0.02 µg L-1 and 0.03 µg L-1, respectively. BiNPs@LPC/SPCE demonstrated remarkable selectivity, stability and repeatability. The proposed method was successfully applied for the detection of Pb(II) and Cd(II) in seafoods achieving satisfying recovery of 97.8%-108.3% and 96.7%-106.4%. These excellent test properties were coupled with convenience for batch preparation of the modified electrodes, highlighting its potential for practical applications in heavy metal detection of real samples.

Short communication: Assessing seromuscular layer and serosa removal on intestinal permeability measurements in weaned piglet everted sac segments.

The integrity of the intestinal barrier is crucial for regulating the passage of pathogens and toxins, while facilitating nutrient absorption. The everted gut sac technique, an ex-vivo technique, can be used to study interventions on barrier function. This cost-effective approach utilizes relatively large gut segments to study specific intestinal regions. Typically, intact (non-stripped) intestinal segments are used, but their use may underestimate permeability due to the medial positioning of blood vessels relative to the seromuscular layer and serosa. However, removing these layers risks physical damage, resulting in an overestimation of intestinal permeability. Therefore, we investigated the impact of stripping jejunal segments on permeability to fluorescein isothiocynate-dextran (FITC, 4 kDa) and tetramethylrhodamine isothiocynate-dextran (TRITC, 40 kDa), and on the absorption of glucose, lysine, and methionine in jejunal segments from 80 piglets at 8 days post-weaning. Piglets were subjected to either high or low sanitary housing conditions and diets provoking intestinal protein fermentation or not, expected to influence intestinal permeability. Stripping of the seromuscular layer and serosa increased the passage of 4 kDa FITC-dextran (stripped vs. non-stripped; 1.1 vs. 0.9 pmol/cm2/min, P<0.001), glucose (40.0 vs. 19.1 pmol/cm2/min, P<0.001), lysine (2.5 vs. 2.0 nmol/cm2/min, P<0.001), and methionine (4.1 vs. 2.7 pmol/cm2/min, P<0.001). As permeability increased, the differences in methionine passage between stripped and non-stripped intestinal segments also increased (slope = 1.30, P=0.009). The coefficients of variation were comparable between stripped and non-stripped intestines (over all treatments, stripped vs. non-stripped 38 vs. 40%). Stripping, by isolating mucosal processes without introducing additional variation, is thus recommended for studies on intestinal permeability or absorption.

Clinical outcomes of nonthermal ablation, thermal ablation, and surgical stripping for varicose veins.

OBJECTIVE: The purpose of this study was to compare the clinical outcomes of radiofrequency ablation (RFA), cyanoacrylate closure (CAC), mechanochemical ablation (MOCA), and surgical stripping (SS) for incompetent saphenous veins and to determine a suitable treatment modality for a specific clinical situation. METHODS: We retrospectively reviewed the data of patients with varicose veins who underwent RFA, CAC, MOCA, or SS from January 2012 to June 2023. The clinical outcomes, including postoperative complications and the Aberdeen Varicose Vein Questionnaire score, were assessed. RESULTS: During the study period, 2866 patients with varicose veins were treated. Among them, 1670 patients (57.9%) were women. The mean age was 55.3 ± 12.9 years. RFA, CAC, MOCA, and SS were performed in 1984 (68.7%), 732 (25.4%), 78 (2.7%), and 88 (3.0%) patients, respectively. The complete target vein closure rate after RFA, CAC, and MOCA was 94.5%, 98%, and 98%, respectively. The absence of a target vein after SS was 98%. Deep vein thrombosis developed in four patients: one in the RFA group and three in CAC group. Surgical or endovenous procedure-induced thrombosis occurred in 2.3%, 4.8%, 6.4%, and 2.3% of the patients after RFA, CAC, MOCA, and SS, respectively. Phlebitis along the target vein occurred in 0.2% and 3.8% of patients after RFA and MOCA, respectively. A hypersensitivity reaction occurred in 3.7% of patients after CAC. Readmission was required for two patients who had undergone SS. Transient nerve symptoms developed in five (0.3%), zero, one (1.3%), and two (2.3%) patients after RFA, CAC, MOCA, and SS, respectively. After treatment, the Aberdeen Varicose Vein Questionnaire score improved significantly in all groups. CONCLUSIONS: The clinical outcomes with improvement in quality of life were comparable among the different treatment modalities. The proximity of the nerve or skin to the target vein is the most important factor in selecting a suitable treatment modality.

Dam-calf contact rearing in Switzerland: Aspects of management and milking.

Cow-calf contact (CCC) rearing is becoming an increasingly popular alternative to the common practice of early separation of cow and calf in dairy management. Milkability can be impaired in nursing cows, which contributes to the loss of machine milk yield caused by calf intake, especially in pure dam-calf contact (DCC) systems. The aims of this study were (1) to describe the current status quo of DCC rearing regarding management and milking and (2) to evaluate the effects of DCC (suckling and milking vs. milking alone) and the effects of different types of DCC on milkabilty parameters, teat condition and behavior during milking on Swiss DCC farms. By means of 17 telephone interviews with DCC farmers, we collected data on DCC management, housing, separation and weaning processes, milking procedures and techniques, and perceived milkability problems. Subsequently, we collected data on 10 of the interviewed DCC farms (183 cows): 4 DCC farms with a whole-day contact (WDC) system, 3 farms with DCC before milking (CBM), and 3 farms with DCC after milking (CAM). Five farms on which calves had no contact with dams were chosen as reference farms (178 cows). Using a milk flow meter, the occurrence of ejection disorders, bimodality of the milk flow curve, machine milk yield, the duration of the decline phase, and the duration of prestimulation were measured. The average mouthpiece chamber vacuum during the main milking phase and hind leg activity during milking were measured using a pressure sensor and an accelerometer, respectively. After cluster removal, the teat condition was evaluated, and a stripping milk sample was taken for fat content analysis. The interview results revealed that 8 of the 17 farms surveyed had a WDC system, and 2 farms operated a daytime DCC system. Contact before milking was applied by 3 farms, and 3 farms allowed CAM. On one farm, calves had access to dams 3 times a day. A great diversity in cow-calf management was found. In the on-farm data-collection, 20 milkings of a total of 701 milkings examined met the criteria for a clear ejection disorder, with 17 of these observations occurring on WDC farms and none on reference farms. The stripping milk fat content was lower in nursing cows, indicating a lower degree of udder emptying. Machine milk yield during the main milking phase was higher in nursing CAM cows than in nursing WDC and CBM cows. Farm types did not differ regarding teat condition, hind leg activity, or the occurrence of bimodal milk flow curves. In conclusion, the large variation in individual management approaches to DCC rearing even within DCC types, such as calf housing or cow breeds, implies caution when interpreting results. Contact after milking may be the system most beneficial for some productivity parameters, but adequate calf supply must be ensured. Higher amounts of milk remaining in the udder after cluster removal indicate that nursing can affect milkability, but future research should consider the effects of udder filling before milking to better interpret the fat content of stripping milk.

Evaluation of Less Invasive Sampling Tools for the Diagnosis of Cutaneous Leishmaniasis.

Background: Diagnosis of cutaneous leishmaniasis (CL) usually relies on invasive samples, but it is unclear whether more patient-friendly tools are good alternatives for diverse lesions when used with polymerase chain reaction (PCR). Methods: Patients with suspected CL were enrolled consecutively in a prospective diagnostic accuracy study. We compared dental broach, tape disc, and microbiopsy samples with PCR as index tests, using PCR with skin slit samples as reference test. Subsequently, we constructed a composite reference test including microscopy, the 3 index tests and skin slit PCR, and we compared these same tests with the composite reference test. We assessed diagnostic accuracy parameters with 95% confidence intervals for all comparisons. Results: Among 344 included patients, 282 (82.0%) had CL diagnosed, and 62 (18.0%) CL absence, by skin slit PCR. The sensitivity and specificity by PCR were 89.0% (95% confidence interval, 84.8%-92.1%) and 58.1% (45.7%-69.5%), respectively, for dental broach, 96.1% (93.2%-97.8%) and 27.4% (17.9%-39.6%) for tape disc, and 74.8% (66.3%-81.7%) and 72.7% (51.8%-86.8%) for microbiopsy. Several reference test-negative patients were consistently positive with the index tests. Using the composite reference test, dental broach, and skin slit had similar diagnostic performance. Discussion: Dental broach seems a less invasive but similarly accurate alternative to skin slit for diagnosing CL when using PCR. Tape discs lack specificity and seem unsuitable for CL diagnosis without cutoff. Reference tests for CL are problematic, since using a single reference test is likely to miss true cases, while composite reference tests are often biased and impractical as they require multiple tests.

Cation-Loaded Porous Mg2+-Zeolite Layer Direct Dendrite-Free Deposition toward Long-Life Lithium Metal Anodes.

Lithium metal, with ultrahigh theoretical specific capacity, is considered as an ideal anode material for the lithium-ion batteries. However, its practical application is severely plagued by the uncontrolled formation of dendritic Li. Here, a cation-loaded porous Mg2+-Zeolite layer is proposed to enable the dendrite-free deposition on the surface of Li metal anode. The skeleton channels of zeolite provide the low coordinated Li+-solvation groups, leading to the faster desolvation process at the interface. Meanwhile, anions-involved solvation sheath induces a stable, inorganic-rich SEI, contributing to the uniform Li+ flux through the interface. Furthermore, the co-deposition of sustained release Mg2+ realizes a new faster migration pathway, which proactively facilitates the uniform diffusion of Li on the lithium substrate. The synergistic modulation of these kinetic processes facilitates the homogeneous Li plating/stripping behavior. Based on this synergistic mechanism, the high-efficiency deposition with cyclic longevity exceeding 2100 h is observed in the symmetric Li/Li cell with Mg2+-Zeolite modified anode at 1 mA cm-2. The pouch cell matched with LiFePO4 cathode fulfills a capacity retention of 88.4% after 100 cycles at a severe current density of 1 C charge/discharge. This synergistic protective mechanism can give new guidance for realizing the safe and high-performance Li metal batteries.

Membrane stripping in group B streptococcus carriers does not impede adequate intrapartum antibiotic prophylaxis: a retrospective study.

Objective: Membrane stripping in group B streptococcus (GBS) carriers poses an increased risk of inadequate antibiotic prophylaxis, potentially due to accelerated labor, thereby potentially impacting the management of GBS colonization during delivery. We compared the adequacy of intrapartum antibiotic prophylaxis between pregnant women colonized with GBS, who underwent membrane stripping and those who did not. The study aimed to determine whether the performance of membrane stripping, by potentially shortening labor duration, increases the risk of inadequate antibiotic prophylaxis dispensation. Study design: A retrospective cohort study was conducted on GBS screen-positive women with a full-term singleton pregnancy in cephalic presentation, who were eligible for vaginal delivery. The exposed group consisted of women who underwent membrane stripping, while the unexposed group consisted of women who did not undergo membrane stripping. The primary outcome was defined as inadequate duration of antibiotic prophylaxis during labor, wherein less than 4 h of beta-lactam antibiotics were administered prior to delivery. Neonatal outcome was compared between the groups. Results: This retrospective cohort study comprised 1,609 women, with 129 in the exposed group (stripping group) and 1,480 in the unexposed group (no stripping group). Adequate intrapartum antibiotic prophylaxis was received by 64.3% (83/129) of the exposed group, compared to 46.9% (694/1,480) of the unexposed group (p = 0.003). Membrane stripping was associated with increased odds of receiving adequate prophylaxis (OR 1.897, 95% CI 1.185-3.037, p = 0.008). After excluding women who presented to the labor ward in active labor and delivered in less than 4 h, both the exposed and unexposed groups had similarly high rates of adequate intrapartum antibiotic prophylaxis (87.5% vs. 85.8%, respectively). No significant difference was observed in adverse neonatal outcomes between the groups. Conclusion: The provision of membrane stripping did not impede adequate intrapartum antibiotic prophylaxis and was correlated with a higher rate of sufficient prophylaxis in comparison to non-swept patients. These observations suggest that membrane stripping can be considered a safe option for ensuring adequate antibiotic prophylaxis in women colonized with GBS.

Nucleation of Pitting and Evolution of Stripping on Lithium-Metal Anodes.

The stripping reaction of lithium (Li) will greatly impact the cyclability and safety of Li-metal batteries. However, Li pits' nucleation and growth, the origin of uneven stripping, are still poorly understood. In this study, we analyze the nucleation mechanism of Li pits and their morphology evolution with a large population and electrode area (>0.45 cm2). We elucidate the dependence of the pit size and density on the current density and overpotential, which are aligned with classical nucleation theory. With a confocal laser scanning microscope, we reveal the preferential stripping on certain crystal grains and a new stripping mode between pure pitting and stripping without pitting. Descriptors like circularity and the aspect ratio (R) of the pit radius to depth are used to quantify the evolution of Li pits in three dimensions. As the pits grow, growth predominates along the through-planedirection, surpassing the expanding rate in the in-plane direction. After analyzing more than 1000 pits at each condition, we validate that the overpotential is inversely related to the pit radius and exponentially related to the rate of nucleation. With this established nucleation-overpotential relationship, we can better understand and predict the evolution of the surface area and roughness of Li electrodes under different stripping conditions. The knowledge and methodology developed in this work will significantly benefit Li-metal batteries' charging/discharging profile design and the assessment of large-scale Li-metal foils.

Ultrasmall and Highly Dispersed Pt Entities Deposited on Mesoporous N-doped Carbon Nanospheres by Pulsed CVD for Improved HER.

Vapor-based deposition techniques are emerging approaches for the design of carbon-supported metal powder electrocatalysts with tailored catalyst entities, sizes, and dispersions. Herein, a pulsed CVD (Pt-pCVD) approach is employed to deposit different Pt entities on mesoporous N-doped carbon (MPNC) nanospheres to design high-performance hydrogen evolution reaction (HER) electrocatalysts. The influence of consecutive precursor pulse number (50-250) and deposition temperature (225-300 °C) are investigated. The Pt-pCVD process results in highly dispersed ultrasmall Pt clusters (≈1 nm in size) and Pt single atoms, while under certain conditions few larger Pt nanoparticles are formed. The best MPNC-Pt-pCVD electrocatalyst prepared in this work (250 pulses, 250 °C) reveals a Pt HER mass activity of 22.2 ± 1.2 A mg-1 Pt at -50 mV versus the reversible hydrogen electrode (RHE), thereby outperforming a commercially available Pt/C electrocatalyst by 40% as a result of the increased Pt utilization. Remarkably, after optimization of the Pt electrode loading, an ultrahigh Pt mass activity of 56 ± 2 A mg-1 Pt at -50 mV versus RHE is found, which is among the highest Pt mass activities of Pt single atom and cluster-based electrocatalysts reported so far.

Evaluation of the Consistency of Two Interproximal Reduction Methods in Clear Aligner Therapy: A Preliminary Study.

Objective: To compare the consistency of two interproximal reduction (IPR) methods in terms of the amount of planned and performed IPR during clear aligner therapy (CAT). Methods: Thirty-four patients who received IPR using hand-operated abrasive strips (Group 1, 20 patients, 162 teeth) and motor-driven 3/4 oscillating segmental disks (Group 2, 14 patients, 134 teeth) during CAT were included in this preliminary study. The consistency between the planned and performed IPR amounts was evaluated within and between groups for teeth and quadrants. Results: In Group 1, the amount of IPR performed on teeth numbers 22 and 43 and in the upper left quadrant was found to be statistically less than that of planned. On the other hand, the amount of performed IPR was statistically higher on tooth number 44 and in the upper right quadrant, whereas it was statistically less on tooth number 33 when compared with the planned amount in Group 2. The inconsistency between the planned and performed IPR amounts were statistically significant only in Group 1 and for teeth numbers 11, 21, 32, 33, and 43. No significant difference was found when the same parameter was compared between the groups. Conclusion: The consistency of IPR was found to be better with the motor-driven oscillating disk system than with the hand-operated IPR strip system.

Electrochemical Detection of Cd2+, Pb2+, Cu2+ and Hg2+ with Sensors Based on Carbonaceous Nanomaterials and Fe3O4 Nanoparticles.

Two electrochemical sensors were developed in this study, with their preparations using two nanomaterials with remarkable properties, namely, carbon nanofibers (CNF) modified with Fe3O4 nanoparticles and multilayer carbon nanotubes (MWCNT) modified with Fe3O4 nanoparticles. The modified screen-printed electrodes (SPE) were thus named SPE/Fe3O4-CNF and SPE/Fe3O4-MWCNT and were used for the simultaneous detection of heavy metals (Cd2+, Pb2+, Cu2+ and Hg2+). The sensors have been spectrometrically and electrochemically characterized. The limits of detection of the SPE/Fe3O4-CNF sensor were 0.0615 µM, 0.0154 µM, 0.0320 µM and 0.0148 µM for Cd2+, Pb2+, Cu2+ and Hg2+, respectively, and 0.2719 µM, 0.3187 µM, 1.0436 µM and 0.9076 µM in the case of the SPE/ Fe3O4-MWCNT sensor (following optimization of the working parameters). Due to the modifying material, the results showed superior performance for the SPE/Fe3O4-CNF sensor, with extended linearity ranges and detection limits in the nanomolar range, compared to those of the SPE/Fe3O4-MWCNT sensor. For the quantification of heavy metal ions Cd2+, Pb2+, Cu2+ and Hg2+ with the SPE/Fe3O4-CNF sensor from real samples, the standard addition method was used because the values obtained for the recovery tests were good. The analysis of surface water samples from the Danube River has shown that the obtained values are significantly lower than the maximum limits allowed according to the quality standards specified by the United States Environmental Protection Agency (USEPA) and those of the World Health Organization (WHO). This research provides a complementary method based on electrochemical sensors for in situ monitoring of surface water quality, representing a useful tool in environmental studies.