Plastic Ring Research Articles

Assessing the impact of packaging materials on anoxic biotrickling filtration of siloxanes in biogas: Effectiveness of activated carbon in removal performance

Siloxanes (VMS) represent a class of organosilicon compounds known for their adverse effects on both the environment and human health. Their presence in biogas significantly hinders its economic valorisation, highlighting the need for effective treatment methods. This study investigates the performance of three different packing materials in the anoxic biofiltration of VMS (L2, L3, D4 and D5). The materials evaluated included plastic rings (BTF-1), polyurethane foam (BTF-2) and plastic rings combined with activated carbon (80:20) (BTF-3). Among them, BTF-3 exhibited superior performance, achieving maximum VMS removal efficiencies (REs) of 90%, including the complete elimination of L3 and D4, and ∼80% removal of D5, attributed to the presence of activated carbon. However, the abatement of L2 was inferior to that of other VMS (<80%), which was attributed to the activated carbon's affinity for larger molecular weights and critical diameters. In contrast, BTF-1 and BTF-2 supported maximum VMS removals of 40%. Notably, neither increasing the trickling liquid velocity from 2 to 4.5 m h⁻1 nor adding Fe-carbon nanoparticles to the solution had any impact on the BTFs' performance. Following the successful results observed in BTF-3, gas residence time was reduced from 60 to 42 min, consequently leading to an increase in the EC from 366 to 509 mg m−3 h−1 (corresponding to an RE = 87%). Despite the different performance of the BTFs, comparable bacterial communities were identified, dominated by the genera Thermomonas, Corynebacterium, Aquimonas, Thauera and Parvibaculum. The results obtained in this study highlighted the potential of activated carbon as packing material for enhancing abatement performance during biotrickling filtration and identified new bacterial genera with potential for VMS degradation.

Corneal melting after paclitaxel therapy in a case with intrastromal corneal ring segment (ICRS) implantation

Intrastromal corneal ring segments (ICRS) are small, crescent shaped plastic rings placed in the deep, peripheral corneal stroma to flatten the cornea. Corneal melting is a rare complication of ICRS implantation, with no long term effects reported. Although ocular toxicities are associated with paclitaxel (PTX), corneal melting from PTX therapy remains rare. Here we report a case of corneal melting in a patient who had ICRS implanted 20 years ago following recent PTX therapy for breast cancer. A 35 year old female patient presented with eye pain, photophobia, and blurry vision in her left eye, following a history of ICRS implantation 20 years ago. She was diagnosed with breast cancer 6 months ago and was undergoing PTX chemotherapy therapy. Ocular examination revealed bilateral meibomian gland dysfunction (MGD) and corneal melting in the left eye at the site of the corneal ring. Treatment initially included only eye drops mainly to promote epithelial repair and control inflammation. After 2 weeks, the corneal melting showed signs of healing; however, the patient continued complaining about eye pain and discomfort. Subsequently, amniotic membrane transplantation (AMT) and corneal contact lenses were initiated, leading to significant improvement after 2 months of treatment.

Evaluasi Penggunaan Alat Pelindung Diri (APD) dalam Pemilahan Sampah AMDK Gelas Plastik di Bank Sampah SiHatin

This study aims to evaluate use of finger protection PPE in process of sorting plastic glass at SiHatin Waste Bank. The waste sorting process with high risk is the process of cutting plastic cup ring. This research uses qualitative method with case study approach, interviews, and observations to identify problems and find solutions to improve comfort and safety. PPE used for three months was proven to increase safety officers by 80.95%. However, there is discomfort experienced by 18 out of 20 officers due to several factors, namely: precision movements difficulty by 90%, sweat on fingers by 60%, inappropriate size by 45% and skin irritation by 35%. The proposed solutions include using more comfortable materials and ergonomic, setting break times, and training use of PPE to increase its effectiveness. In addition, development of cutting ring tool was developed to reduce the risk of injury and increase worker productivity.

Bulking agent in dry anaerobic digestion as a key factor for the enhancement of biogas production

Dry anaerobic digestion (dry-AD) is an attractive process for solid wastes such as agri-food waste. However, some limitations mainly associated to lack of effective mixing, can hinder the methane production capacity of the systems. Bulking agent (BA) has been proposed as a solution to the compaction issues in systems without mechanical agitation, such as leaching bed reactors. However, effects of BA are still not clear, and, thus, the factors to consider for its dose has not been optimized yet. This work studies the effect of BA in dry-AD. Two substrates with different characteristics were proposed as models, bean peel as a lignocellulosic substrate and a mixture of food waste as a readily biodegradable substrate. Inert plastic rings were used as BA at different BA:S ratios. Assessed BA:S ratio did not affect the performance of methane production for the lignocellulosic waste, but it did significantly affect to the easily biodegradable substrate, showing up to a 28% of methane production increase. This result could be due to the presence of lignocellulosic compounds in the bean peel, behaving like a natural BA. In assays with an increased bed height, the compaction of the system was more severe, resulting in the rapid acidification of the processes. At these conditions, the positive effect of BA addition was more marked, allowing methane production and no acidification of the system. Thus, the addition of BA is a suitable strategy for improving methane production or stability in dry-AD systems without requiring the stirring of the systems.

Research Status of Friction Interface Evolution Mechanism of Non-magnetic Steel

The non-magnetic drill pipe (composed of male and female thread joints and rod bodies) is the key component of the directional drilling technology equipment for gas extraction in coal mine tunnels. The thread joint and the drill pipe body are connected by continuous drive friction welding. In the study, it was found that the banded structure appeared in the joint of continuous drive friction welding of non-magnetic steel, which reduced the strength of drill pipe. At the same time, it is found that the heat flow mode is one of the key factors affecting the banded structure, and the heat flow mode is based on the evolution of the interface plastic ring. In this paper, through the review of the research status of the interface evolution law of non-magnetic steel continuous drive friction welding, the experimental method for the study of the interface evolution law of non-magnetic steel continuous drive friction welding is found.

Hold my beer! Consumer perceptions of innovative and sustainable secondary packaging

PurposeAs a result of both shifting social concerns and stricter legislation, many companies are seeking innovative and sustainable solutions for both primary and secondary packaging. The craft beer industry has made the most notable advancements with a variety of alternatives to the traditional secondary packaging (e.g. plastic rings) used to link beer cans. Yet, despite the impact packaging has on consumer purchase behavior and the environment, secondary packaging has received far less attention in the literature. This study aims to understand consumer perceptions of craft beer secondary packaging on consumers’ willingness to buy via the underlying mechanisms of perceived packaging innovation and sustainability.Design/methodology/approachA single-factor between-subjects experiment with four conditions (secondary packaging format: Pak-Tech holder, Keel Clip holder, Glue-Pack holder, Biodegradable holder) was conducted with 354 participants to test the hypothesized serial mediation model.FindingsThe results demonstrate that none of the secondary packaging styles had a direct effect on willingness to buy, meaning that the package style alone does not influence a consumer’s purchase decisions. Critically, the results also revealed indirect effects; specifically, the Keel Clip and Glue-Pack six-pack can holders were perceived as more innovative than the Pak-Tech holder, which in turn positively influenced perceptions of packaging sustainability and subsequent willingness to buy.Originality/valueThe authors’ results extend the research on sustainable secondary packaging and aids craft breweries along with other beverage producers in making informed decisions as the push for sustainable packaging becomes more prominent.

Surface treatments for polyetheretherketone (Peek): Effects on the bond strength to a resin cement and on the fatigue performance of a bonded glass-ceramic

ObjectiveTo evaluate the effect of distinct surface treatments on Peek (polyetheretherketone) adhesion to the resin cement and the mechanical fatigue behavior of lithium disilicate adhesively bonded to it. Materials and methodsPeek slices embedded in plastic rings with self-curing acrylic resin were randomized into 4 groups for adhesion testing, considering the following surface treatment factors: Ctrl (just cleaned with 78 % isopropyl alcohol); Grinding (4219F diamond bur - 46 μm grain size); Air abrasion (45 μm aluminum oxide for 10 s); Sulfuric acid (acid etching for 30 s). All slices received a layer of adhesive agent; resin composite cylinder specimens (Ø = 3 mm; h = 3 mm) were produced and bonded onto the Peek slices using a dual resin cement for the shear bond strength tests (n = 20) through the wire-loop technique. Next, disc-shaped specimens of Peek (Ø = 10 mm; thickness: 2 mm) and lithium disilicate (LD) (Ø = 10 mm; thickness: 1 mm) were produced for the fatigue tests (n = 20) and paired. The LD was treated (5 % hydrofluoric acid for 20 s + silane agent) and adhesively bonded (with dual resin cement) onto Peek (treated with the previously mentioned surface treatments). The fatigue tests were performed with a step-stress approach (20 Hz; 10,000 cycles/step; initial load: 100 N; step-size: 50 N). Roughness, contact angle, topography and fractographic analysis were performed. The adhesive data was analyzed by one-way ANOVA and Tukey post-hoc tests, while the fatigue data were subjected to survival analysis (Kaplan Meier and Mantel-cox post hoc tests). ResultsOnly the air abrasion surface treatment was able to improve the bond strength between Peek and resin cement (p < 0.05); the Grinding and Sulfuric acid groups were similar to the Ctrl. All surface treatments promoted similar fatigue performance. ConclusionAir abrasion promoted increased bond strength between Peek and resin cement, having no detrimental effect on fatigue behavior. Overall, the mechanical behavior under fatigue of a lithium disilicate glass-ceramic was not influenced by the Peek substrate surface treatments.

Enhancing the damping effect of MRF damper using an external magnetic excitation system

The magnetic field generated by the damper’s magnetic circuit governs the yield stress value of the Magnetroholgical Fluid (MRF) damper and hence its damping effect. This paper contributes to the literature on the development of MRF dampers by introducing a new design feature to improve the damper’s performance. The presented novel feature tends to amplify the magnetic field value and concentrate its flux within the MR fluid region. The excitation sources consist of 12 coils placed in radial directions surrounding the MRF to focus the energizing magnetic effects. However, the search for efficient solutions is not only focused on generating more energy but also on minimizing its loss. Therefore, a metallic ring was placed around the coils to close the magnetic circuit, guide the flux lines, and avoid any energy dispersion to the surrounding air. As a proof of concept, two materials were tested for the surrounding ring: plastic acrylonitrile butadiene styrene (ABS) and mild steel. The performance of both solutions was assessed experimentally with a Gaussmeter and numerically by using a model developed via COMSOL Multiphysics. Both techniques confirmed the efficiency of the solution based on a steel ring in preventing the flux dispersion into the surrounding air. In addition, an increase of the excitation current from 0 to 5A was found to elevate the magnetic field by 35%, compared with the ABS ring. In the second step, a test rig was designed and built to investigate the damping efficiency of the MRF experimentally. The testing apparatus consisted of a sliding-bearing mechanism connected to a variable speed motor. The damping effect was assessed based on the force and displacement data provided by a linear variable displacement transducer (LVDT) and a force cell. Damping forces were observed at a constant frequency of 0.36 Hz (22 rpm) when the testing system and the attached damper were functioning smoothly away from its resonant frequency. Moreover, the magnetic field excitation current was elevated from 0 A to 5 A with a 1 A step. Again, the metallic ring was found to produce a 112% greater damping coefficient than the case of the plastic ring when the excitation current reached 5A.

A new obesity treatment method that does not require restriction in food intake and organ resection

Background/Aim: There are numerous treatment methods available for obesity, with bariatric surgery being the most effective. However, these techniques come with the risk of serious complications. This study presents a novel obesity treatment device that can shorten the length of the small intestine without the need for surgical intervention. Methods: Our new device comprises three main components: a 25 cm long rope, with one end attached to a 1 cm diameter plastic ring and the other end attached to a 2 mm diameter, 5 g sphere. Twenty-one male Wistar albino rats (6 months old, mean weight 400 g, outbred) were divided into three equal groups. Laparotomy and gastrotomy were performed on the subjects in Group 1, and all three parts of the device were placed into the gastrointestinal tract. In Group 2, only the plastic ring was placed in the stomach, and in Group 3, only a gastrotomy was performed. All subjects were followed for 3 months, during which their body weight, serum ghrelin, leptin, and nesfatin-1 levels were recorded, and the amount of food they consumed was measured. After sacrificing the animals, the stomach, proximal, and distal intestines were resected for histopathological evaluation. Results: The subjects in Group 1 experienced weight loss, whereas those in Groups 2 and 3 showed statistically significant weight gain (P&lt;0.001 and P=0.022, respectively). Serum ghrelin levels were significantly increased in Groups 1 and 3 (P=0.015 and 0.031, respectively), while serum leptin levels were significantly decreased in Group 1 (P=0.015). Plasma nesfatin-1 levels were significantly higher in Group 1 compared to the other groups (P=0.014). There was no statistically significant difference in feed consumption between the groups. Histopathological examination revealed significantly higher fibrosis and inflammation scores in the proximal small intestine of Group 1 compared to the other groups (P=0.008 and P=0.005, respectively). Conclusions: This new device facilitates rapid and effective weight loss without the need for restricting oral food intake or organ resection. Changes in serum ghrelin, leptin, and nesfatin-1 levels did not affect these results. We hypothesize that the effective weight loss is linked to the shortening of the small intestine length. Our future plans involve modifying the device for endoscopic application in humans.

Strangulation of the Verge by Plastic Ring

We report the case of a 73-year-old Parkinsonian patient, admitted to the emergency department of the Moulins yzeure hospital center, for penile lymphedema evolving for 7 hours after the voluntary placement of the rod in the neck of a plastic bottle to urinate in. The removal of this ring was immediately performed under general anesthesia in the OR after several attempts under local anesthesia that failed. Seven days later, the patient showed a marked improvement with regression of the skin signs, the skin was more supple and less infiltrated. At the exit the patient was programmed for a cold posthectomy. Through this observation and the data of the literature, we specify the management of this pathological situation and the associated complications.

Possibilities of improving the technique of controlled transosseous osteosynthesis in the conditions of anatomical experiment

The possibilities of improving controlled transosseous osteosynthesis in anatomical experiment by changing the design of the external fixation apparatus by individualizing the design of the apparatus, ensuring accurate dynamic reposition of bone fragments, and establishing more effective X-ray control using X-ray transparent elements of the external fixation apparatus design are considered. The study was performed under wet preparations of an isolated femur of ten rabbits with a bone diaphysis fracture created. The original compressiondistraction apparatus of external fixation developed was experimentally approved. In all experiments, an accurate comparison of bone fragments was obtained by dynamic reposition owing to the use of autonomous hinge modules and the presence of an individualized base module located in the pathological focus of the bone structure. The study showed the need to individualize the size of the design of the elements of the device. This is because the damaged limb does not have the correct cylindrical shape, unlike the shape of the apparatus. Changing the morphometric parameters of the damaged limb segment during osteosynthesis requires a specific individual geometry of the base module. The individualization of the shape and size of the base module should provide for the possibility of implementing the stages of moving fragments of bone structures, individual in each case. The dimensions of the X-ray transparent plastic ring or the shape of the hinge module close to the ring should correspond to the geometric dimensions of the limb segment at the fracture site and subsequently when correcting the position of bone fragments in each individual case. The most often optimal is the distance from the supports of the device to the surface of the limb segment of 5 cm, which determines the geometric dimensions of the individualized base module. In general, the directions of further improvement of the hardware of the technique of controlled transosseous osteosynthesis are determined. The effectiveness of X-ray control owing to the use of X-ray transparent structural elements of the device is shown. It has been revealed that in the conditions of anatomical experiment, controlled transosseous osteosynthesis may be more effective by improving the hardware owing to the individualization of the structural elements of the apparatus in combination with the use of autonomous hinge modules.

The Thermal Conductivity and Matric Potential (Moisture Tension) Relationships for Soils of Different Gypsum Content

The soil samples have been taken from a soil profile at the Research Station of College of Agriculture in the University of Tikrit at a longitude of 430 38- 23= in the east and at a latitude of 340 48- 40= in the north. The samples were taken from the surface horizon with a gypsum content of 62 g.kg-1 (G1) and also from the subsurface horizon of 443g.kg-1 (G7) gypsum content. Different gypsum content samples were prepared as G2, G3, G4, G5, and G6 that have Gypsum contents of 106, 153, 202, 245, and 337 g.kg-1 respectively. These samples were prepared by mixing the surface soil samples with the soil of gypsic horizon. The prepared soil samples were wetted by water spraying to two thirds the field capacity levels (0.25 kg.kg-1). Then they incubated for two months in order to make soils homogeneity in addition to moisture distribution in soil. The plastic rings of 10.4 cm diameter and 10 cm heights were drilled from the middle to fix the sensor of heat flux of thermometer plug. The size and height of the soil to be placed in the plastic ring was calculated based on the area A and height h of ring and then the mass of the soil (m) was calculated based on the value of the bulk density. The samples were oven dried at 70° degree until the weight of samples were fixed to obtain the completely dry soils. The amount of water to be added per sample was calculated based on the moisture characteristics curve and by the tensions specified in this study (0.1, 5, 15, 33 and 100) kPa. The moisture was converted to a depth of water and then soil samples were wetted in a light spraying manner with continuous flipping and the thermometer sensors were fixed up and down the heat flux sensor and then six readings per replication were recorded. The time from one reading to another was 60 seconds and their rate was extracted. Based on the results of the experiment, it can be concluded that by the fixation of moisture tension, the thermal conductivity values of the soil decreased with the increased soil content of gypsum, as the G3 treatment with gypsum content 15% gave the highest significant value while the least significant average value of thermal conductivity values at the G7 treatment with gypsum content was 43%. The increase in gypsum from 25% at G5 to 30% and 44% in G6 and G7 successive treatments did not significantly affect the values of the soil’s thermal conductivity averages. The overlap point of the relationship between soil gypsum content and thermal conductivity was found at G3 and G4 that have gypsum content of 15% and 25% respectively. The average of gypsum decreases the thermal conductivity values of the soil with increased moisture tension values, as the tension gave 0.1 kPa a significant increase in the values of the average thermal conductivity from the rest of the tensions and for all treatments while the least significant average of thermal conductivity values at tension was 100 kPa.

Circumcision: What You Need to Know

Parents have different opinions about newborn male circumcision based on medical, religious, cultural, and ethnic traditions and personal reasons. Some parents choose circumcision. Some parents do not choose circumcision. Parents who are undecided should talk with their child’s doctor before their baby is born. They can learn about the benefits and risks of circumcision to help them choose what is best for their baby. Here is more information from the American Academy of Pediatrics (AAP) about circumcision.At birth, males have skin that covers the end of the penis, called the foreskin. Circumcision is the surgical removal of the foreskin, exposing the tip of the penis. Circumcision is usually performed by a doctor in the first few days after birth. The surgery should be done under sterile conditions with adequate pain management. (See Is circumcision painful?) A newborn must be stable and healthy to safely be circumcised. Because circumcision may be riskier if done later in life, parents should decide before or soon after their baby is born if they want it done.Yes. However, there are pain medicines that are safe and effective. The AAP recommends that they be used to reduce pain from circumcision.After the circumcision, the tip of the penis may seem raw or yellowish. If there is a bandage, it should be changed with each diapering to reduce the risk of infection. Use petroleum jelly to keep the bandage from sticking. Sometimes a plastic ring is used instead of a bandage. This should drop off within 5 to 8 days. The penis should be fully healed in about 1 week to 10 days after circumcision.Problems after a circumcision are very rare. However, call your child’s doctor right away if If you choose not to have your baby circumcised, talk with your child’s doctor about how to keep the penis clean. Keep in mind that the foreskin will not fully retract for several years and should never be forced. When your child is old enough, they can learn how to keep their penis clean just as they will learn to keep other parts of their body clean. Female genital mutilation has sometimes been called female circumcision, although it has no known medical benefits and causes many known harms, both medical and psychological. It involves removing part or all of a female’s clitoris. It may also include sewing up the opening of the vagina. It is often done without any pain medicine. The purpose of this practice is to prove that a female is a virgin before marriage, reduce the ability to experience sexual pleasure, and promote marital fidelity. There are many serious side effects, includingThe AAP is absolutely opposed to this practice in all forms because it is disfiguring and has no medical benefits.Visit HealthyChildren.org for more information.The American Academy of Pediatrics (AAP) is an organization of 67,000 primary care pediatricians, pediatric medical subspecialists, and pediatric surgical specialists dedicated to the health, safety, and well-being of all infants, children, adolescents, and young adults.In all aspects of its publishing program (writing, review, and production), the AAP is committed to promoting principles of equity, diversity, and inclusion.The information contained in this publication should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.

Bearing Characteristics of Multi-Wing Pile Foundations under Lateral Loads in Dapeng Bay Silty Clay

This study provides a theoretical basis for reinforcement of the soil around multi-wing piles. Limit analysis was used to determine the ultimate lateral capacity (ULC) of three- and four-wing piles in Dapeng Bay silty clay. The effects of the pile–soil interaction coefficient α, wing width Bw, and lateral-load direction β on the ULC of the pile and the shear plastic zone range of the surrounding soil were analyzed. The normalized ULC of the three-wing pile decreased when the wing–diameter ratio increased. When Bw was 0.15 m and α was 0.4, the ULC of the four-wing pile was 19% higher than that of the three-wing pile. As β increased, the normalized ULC of the four-wing pile decreased, whereas that of the three-wing pile went through a minimum at 30°. The size of the soil shear plastic ring did not depend on α for either pile type; it increased around the three-wing (but not the four-wing) pile with changes in β. However, there was also a double plastic ring of broken soil around the four-wing pile. The four-wing pile had a more symmetrical influence on the soil around the pile than the three-wing pile.

Effect of passive cell immobilization of co-cultured yeasts on the whey fermentation and alcohols production

Whey is one of the main residues of the dairy industry and its valorization by fermentation is an emergent practice that contributes to the circular economy and sustainable development. Whey fermentation with specialized yeast strains produces value-added biomolecules, such as fusel alcohols of high interest for the pharmaceutic, food and cosmetic industries due to their aromatic and flavor properties. The present study aimed to develop the whey fermentation with the yeasts Kluyveromyces marxianus and Debaryomyces hansenii immobilized on inert support, to increase cell density and 2-phenylethanol (2-PE) production. Biochar synthesized from wood feedstock, perlite and filter Kaldnes plastic rings were used as supports for the cell immobilization. They were selected based on their different nature and physical properties such as porous structure and rough surface, to study the effect of different supports on yeast biofilm development. Also, functional groups such as hydroxyl, carbonyl, siloxane, and aliphatic hydrocarbons were useful for the development of covalent bonds and electrostatic forces between cells-support. The yeast immobilization increased the 2-PE production, especially on the plastic rings and perlite, obtaining 0.56 ± 0.01 g/L of 2-PE for the suspended culture and up to 0.91 ± 0.01 g/L for the immobilized co-culture on filter Kaldnes plastic rings.

3. Assessment of in vitro dural repair techniques with a hydrostatic pressure device

<h3>BACKGROUND CONTEXT</h3> Incidental durotomies are a relatively infrequent occurrence during lumbar spine surgery and are generally benign, without significant adverse consequences. Treatment with direct repair, with or without augmentation, is generally very effective and further cerebrospinal fluid (CSF) leak is uncommon. The strength and stability of a dural repair is dependent on several factors, including patient age, quality of dural tissue, the size and location of the durotomy, and the manner in which the repair is performed. There is limited in vitro evidence comparing the strength of different dural repair techniques and the resulting likelihood of recurrent CSF leak. <h3>PURPOSE</h3> To compare the strength and stability of various dural repair techniques in an in vitro human cadaveric durotomy model. <h3>STUDY DESIGN/SETTING</h3> An in vitro testing device was created to apply controlled, hydrostatic pressure to evaluate the integrity of a surgically-created durotomy. <h3>PATIENT SAMPLE</h3> Sixteen human cadaveric specimens. <h3>OUTCOME MEASURES</h3> The hydrostatic pressure required to cause a leak at the site of the dural repair. <h3>METHODS</h3> Complete human cadavers were placed in the prone position and the dura in the thoracic and lumbar spines was exposed through a midline incision and subsequent laminectomies. The dura was clamped 8 cm proximal and distal to the level of the durotomy and clamped with reliable, water-tight plastic rings. A 16-gauge plastic catheter was introduced into the lateral aspect of the dura and sutured in a water-tight fashion to serve as the source for instilling saline into the dura. The catheter was attached to a hydrostatic pressure measuring column to assess the intradural pressure. Linear durotomies of either 1 cm or 6 cm in length were made with a 15 blade in both the thoracic and lumbar spines of each cadaver. A dural repair was performed with either a 6-0 prolene or 2-0 silk suture. Repair technique were either multiple, simple interrupted sutures or a simple running repair with knots at the respective margins of the durotomy. An analysis of variant analysis (ANOVA) was employed to assess differences in leak rates with respect to applied hydrostatic pressure. <h3>RESULTS</h3> Eight repair groups (thoracic vs lumbar / 6-0 prolene vs 2-0 silk / running vs multiple interrupted) were studied for each of the 1 cm and 6 cm durotomies. There were no significant differences noted in the frequency or extent of spinal fluid leak at different hydrostatic pressures with respect to either suture type employed or suture technique performed. There was a slight difference in the mean applied hydrostatic pressure applied to create a fluid leak in the 6 cm durotomy (16 cm H2O) compared to the 1 cm durotomy (12 cm H2O) but this did not reach statistical significance. <h3>CONCLUSIONS</h3> In this in vitro study of the integrity of the repair of experimentally created durotomies, no significant difference was noted with respect to different suture type or technique of repair. Larger durotomies had a slight, not significant trend for recurrent leak at lower applied hydrostatic pressures. In general, expansion of the repaired dura with controlled delivery of intrathecal fluid, simulating an in vivo, intraoperative Valsalva maneuver, did not reveal significant differences in varying repair types. While this in vitro study does not directly replicate an in vivo scenario, the results do reinforce the necessity of a meticulous water tight suture repair to adequately treat incidental durotomies and thus avoid the troublesome consequences of a recurrent CSF leak. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Investigating the Cytotoxicity of Dual-Cure Bulk-Fill Resin Materials on L929 Cells

The aim of this in vitro study was to investigate cytotoxic effects of dual-cure bulk-fill resin materials polymerized with a third-generation LED light-curing unit (LCU) on L929 fibroblast cells in terms of morphology and viability. Three novel dual-cure, flowable bulk-fill materials (Fill-Up!™), a bioactive material (ACTIVA™ BioACTIVE-RESTORATIVE™), and a dual-cure bulk-fill composite material (HyperFIL® HAp) polymerized by LED LCU (VALO™ Cordless) were tested. Each material was placed in plastic rings (4 mm × 5 mm) in a single layer. Unpolymerized rings filled with each material were placed in direct contact with cells and then polymerized. After polymerization, the removed medium was readded to wells. In this study, four control groups were performed: the medium-free control group, medium control group, physical control group, and light applied control group. Three samples were prepared from each group. After 24 h, the morphology of cells was examined and a WST-1 test was performed. The percentage of cell viability (PCV) of each group was calculated. The experiment was repeated three times. Data were analyzed by a Kruskal–Wallis Test and a Mann–Whitney U test. p &lt; 0.05 was considered significant. The PCV of all groups were found to be significantly lower than the medium control group (p &lt; 0.05). The lowest PCV was obtained in HyperFIL® Hap, while highest was in the Fill-Up!™. In the morphology of cells related to the experimental groups, it was observed that the spindle structures of cells were disrupted due to cytotoxicity; cells became rounded and intercellular space increased. There were no significant differences between the control groups (p &gt; 0.05). All control groups showed acceptable PCV (&gt;70%) and cells were spindle-like, similar to the original fibroblast cells. It can be suggested that clinicians should pay attention when applying dual-cure bulk-fill materials in deep cavities, or they should use a liner material under these materials.

Surgical Correction of Tricuspid Component of Patients with Multi-Vessel Heartdefect.

The analysis of results of surgical correction of 326 (8%) patients with tricuspid pathology in rheumatic multi-valve heart defects. The age of our patients ranged from 12 to 74 years (mean 36.7 + 9.4). Women were 220 (67.5%), while men - 106 (32.5%). According to the degree of circulatory disorders, patients were divided according to the classification of chronic heart failure (CHF) in NYHA, where in functional class III were assigned 24 (7.4%), and to IY functional class NYHA - 302 (92.6%) patients. The clinic is the most commonly used plastic fibrous ring by De Vega. Of the 262 (80.5%) operated by the method of De Vega, at 26.9% after correction of regurgitation on tricuspid valve (TC) virtually disappeared, at 62.8% - regurgitation decreased from a low of 1 degree, and the remaining 10.3% were operated last was reduced to 2 (moderate) degree. In 8 (2.46%) cases of infective endocarditis was made "open" correction - prosthetics TC biological prosthesis. Known methods of creating a bicuspid tricuspid valve - Kay Reed Kay Boyd used in 13.4% of cases, but in recent years because of the low efficiency of data communication techniques greater preference for annuloplasty by De Vega.

The Influence of Sugar Composition and pH Regulation in Batch and Continuous Acetone–Butanol–Ethanol Fermentation

Acetone–butanol–ethanol (ABE) fermentation is influenced by external conditions. This work aimed to study the influence of pH regulation on monosaccharide composition in batch and continuous fermentation processes to determine butanol production and productivity. Batch fermentations with ammonium acetate or calcium carbonate combined with minimum pH control (pH ≥ 4.8 or 5.1) were assessed with pure xylose and glucose/xylose mixtures (ratios of 1:1 and 3:1). Continuous two-stage fermentation was developed using plastic rings to retain the biomass. Although batch fermentations with pure xylose performed better without active minimum pH control with both buffers, minimum pH control was necessary to metabolize xylose in the presence of glucose. Xylose uptake was favored by the use of calcium carbonate and pH ≥ 5.1 at a ratio of 1:1, while ammonium acetate and a pH ≥ 4.8 was the best option for a 3:1 ratio. The best butanol production and productivity values with sugar mixtures in batch reactors were 8.8 g L−1 and 0.61 g L−1 h−1 with an ammonium acetate pH ≥ 4.8 (ratio 3:1). The glucose/xylose ratio combined with pH regulation thus modulated xylose metabolism and solvent production in batch modes. Immobilized cells combined with operating at D = 0.333 h−1 and pH regulation increased butanol productivity almost fourfold up to 2.4 ± 0.2 g L−1 h−1.

A Novel High Flow Rate Pin for Water-assisted Injection Molding of Plastic Parts with a More Uniform Residual Wall Thickness Distribution

Abstract Three types of water pins are currently used in the water-assisted injection molding technologies to mold plastic parts, including orifice, ring and piercing type pins. Nevertheless, the former two types of pins have the disadvantages of a low flow rate and high pressure drop, while the drawbacks for the latter type are that timing the piercing pin into the cavity is a challenge and the cost of a mold is high. This report describes the development a novel high flow rate water pin for water-assisted injection molding of plastic parts. The pin, which consists of a sintered porous surface outlet, has been tested on parts with two different geometries: a plate with a channel across the center and a float-shaped tube part. The experimental results suggests that the proposed water injection pin can mold parts of a large size with a more uniform residual wall thickness distribution.