Sterilization Process Research Articles

Biodegradation of Benzophenone-3 in Non-Sterile Culture Process Using Klebsiella huaxiensis W2

Benzophenone-3 (BP3) is an organic pollutant widely detected in soil and aquatic environments. The aims of this study were to isolate a bacterium which is capable of degrading BP3 and converting it into non-toxic products, and to design a non-sterile culture process which may be applied to the real biological treatment systems for the bioremediation of BP3. Klebsiella huaxiensis W2 (GenBank accession number: PQ143284) isolated from a wastewater treatment system was found to have high potency to degrade BP3. This bacterium degraded BP3 into two byproducts: phenol, 2,4-bis-(1,1-dimethylethyl) and benzyl benzoate. Oxygenases (P450 monooxygenases, dioxygenases etc.) were predicted to be effective in BP3 degradation. BP3-degradation products did not cause a toxicity on fibroblast cell line. Optimizing inoculum size, that is, inoculating the high size (1–2%) of the bacterial preculture into the wastewater-based medium, make the bacterium more dominant in this medium, thus enabling the bacterial cells to degrade BP3 under non-sterile culture conditions. In this process, biodegradation efficiency was not affected notably from temperature variations, and the bacterium was able to hydrolyze about 99.33% of 1 g/L BP3 within 120 h. Overall, K. huaxiensis W2 was deduced to possess the potency for being used as a bioremediation agent in non-sterile biological treatment systems, in which sterilization process, temperature control, and nutrient supplementation were not needed. The designed process may find applications in the bioremediation of wastewater and sewage effluents. This is the first study using K. huaxiensis in a non-sterile environment for BP3 degradation.

Management of risks linked to the sterilization of reusable medical devices in dentistry

The aim of this study was to analyze the risks associated with the sterilization process for reusable medical devices (RMD) in stomatology, by applying the FMECA method, with a view to implementing the necessary corrective and preventive actions necessary to secure this process. The study, which was descriptive, took place between June and July 2024 in the medicine and dental surgery department of our hospital and concerned the moist heat sterilization process of RMD. The study began by defining its scope and the formation of the work team, followed by the functional analysis of the process, the identification of the failure modes (FM), the definition of the rating scales, the rating of the FM and finally the calculation of the criticality index and the development of the action plan. A total of 64 FM were identified, including 14 of high criticality, 16 of medium criticality and 34 of low criticality. The pre-disinfection and cleaning stage generated the most failures, particularly those of high criticality. High criticality FM were subject to a set of corrective and preventive actions. A new map of the sterilization process highlighting a 'forward march' flow has been proposed. Our FMECA made it possible to highlight several FM and propose an appropriate action plan. A second FMECA would still be interesting to evaluate the reduction in the overall criticality of our process.

Development of a sterilization process for amniotic membrane allograft tissue using supercritical carbon dioxide and NovaKill

Amniotic membrane is arguably one of the most popular biological wound dressings on the market today. Various growth factors and cytokines inherent to amniotic membrane tissue have been recognized as key mediators in wound healing and tissue regeneration, giving the tissue its clinical utility. Sterilization methodologies using irradiation are recognized as the gold standard in the field and routinely used to prepare tissue allografts, including amniotic membrane for transplantation. However, irradiation is not always compatible in preserving the physical structure or biochemical factors of biological materials and can potentially result in detrimental effects to the critical quality attributes of allograft tissues. Alternatively, a novel sterilization technique involving supercritical carbon dioxide (SCCO2) has been shown to have minimal effect on the inherent biophysical properties of sensitive biological tissues and tissue-derived products. At BioBridge Global, we have developed a process utilizing SCCO2 technology for the sterilization of an amniotic membrane tissue allograft product. This process, first and foremost, meets industry standards for sterilization while simultaneously maintaining the biochemical composition of the tissue. Our results show that upon SCCO2 sterilization, most of the growth factors tested were conserved, with many at quantities significantly greater than commercially available gamma and electron beam irradiated tissue. The SCCO2-sterilized amniotic membrane allograft is unique in that it is designed to overcome limitations associated with traditional tissue sterilization methodologies, namely, the conservation of key biological factors inherent to native amniotic membrane tissue. It is anticipated that by retaining these biological factors, clinical outcomes associated with the use of SCCO2-sterilized amniotic membrane will be improved.

Decellularization techniques pave the way for tissue engineering and regenerative medicine: a narrative review

Decellularization refers to the removal of cellular components from animal tissues or organs via specific methods to obtain an extracellular scaffold comprising an extracellular matrix. Physical, chemical, and biological methods can be used to remove cellular components from tissues or organs. The obtained decellularized extracellular matrix retains both the original structural framework and bioactive components and significantly reduces immune rejection. This is an ideal three-dimensional scaffold for cell growth and tissue repair. Despite the remarkable progress in decellularization technology, some challenges remain. For example, how to achieve efficient and uniform decellularization without compromising the integrity and bioactivity of the extracellular matrix, how to ensure that sterilization methods do not damage the structure and function of the decellularized extracellular matrix, and how to improve the clinical safety and efficacy of the decellularized extracellular matrix are important. This paper delves into various methods of decellularization, evaluation techniques of decellularized extracellular matrices, and their potential applications in multiple fields of organ regeneration, bio3D printing, and disease modeling, with a special emphasis on the critical role of decellularized extracellular matrices as bioinks in bio3D printing to support cell adhesion and differentiation, highlighting the significant value of decellularization technology in the construction of complex biological structures. The use of the extracellular matrix as a bioscaffold can better support cell growth and functional recovery. By optimizing the decellularization and sterilization processes, the performance of decellularized extracellular matrix can be further improved to advance its progress in clinical applications. In conclusion, the clinical application of decellularized extracellular matrix, which can be used for repairing damaged tissues, customizing personalized therapeutic solutions, and developing new drug testing platforms, is promising. Further research and application of decellularized extracellular matrix are expected to advance the development of regenerative medicine, thereby providing patients with safer and more effective treatment options.

Differences and mechanisms of color deterioration in three types of ready-to-eat shellfishes during storage.

Ready-to-eat (RTE) abalones, scallops and oysters were prepared through a process of cooking, drying, vacuum packaging, and high-temperature sterilization, and were subjected to accelerated storage. Upon storage, the three RTE shellfishes all showed color deterioration, as indicated by darker color, decreased L* and W* values, and increased a* value. In contrast, the color deterioration of RTE oysters was more pronounced. Meanwhile, oxidation reactions occurred during storage, which were manifested as increased peroxide value, thiobarbituric acid reactive substances value and aldehyde content. Correlation analysis showed that the color indexes (L* and W*) of the three RTE shellfishes were negatively correlated with the contents of 5-hydroxymethylfurfural, hydrophilic pyrroles, hydrophobic pyrroles and quinones, suggesting that Maillard/Maillard-like reactions and phenolic oxidation reaction contributed to the color deterioration. The higher contents of reducing sugar, lipids and transition metal ions in RTE oysters make it more prone to non-enzymatic browning reactions, causing faster color deterioration.

Mechanical and Physicochemical Properties of Ti6Al4V Alloy After Plastic Working and 3D Printing Intended for Orthopedics Implants

The aim of this study was to compare the mechanical and physicochemical properties of Ti6Al4V alloy samples produced using 3D printing (Direct Metal Laser Sintering) and bar after plastic working. Both sets of samples were subjected to various surface-processing methods, including sandblasting, heat treatment (hardening for 120 min at 820 ± 10 °C, followed by cooling to room temperature), mechanical polishing, and steam sterilization. This research included macroscopic surface evaluation before and after pitting corrosion resistance tests, metallographic microscopic research, scanning electron microscopy, and energy-dispersive spectroscopy, as well as measurements of hardness, roughness, and surface wettability. The results showed that heat and surface treatment (grinding and mechanical polishing) significantly increased the material’s hardness and corrosion resistance. Furthermore, the steam sterilization process had a positive effect by increasing surface wettability, which is important for biomedical applications, as higher wettability promotes better integration with biological tissues. This is especially relevant in implantology, where surface properties influence osseointegration and overall biocompatibility. In summary, these findings indicate that the selection of manufacturing method and the application of subsequent treatment processes significantly affect the mechanical and physicochemical properties of Ti6Al4V alloy, thereby influencing its performance and suitability for diverse engineering and biomedical applications.

Interaction of preservatives with contact materials during filling and storage of parenteral liquid formulations

Silicone tubing is a frequently used material in pharmaceutical filling processes for parenteral formulations, as its characteristics like flexibility, chemical resistance and easy handling make it particularly suitable for these purposes. This study investigated the time-dependent interaction of phenol and m-cresol with silicone tubing and other broadly applied contact materials used during the filling and transport processes of parenteral formulations. Phenol losses could be observed after incubation in silicone tubing, depending on the inner diameter (ID). This has been demonstrated for process interruptions of up to 120 minutes. A loss of 40 % could be observed for a small ID of 3.2 mm which can be found close to filling needles, and up to 12 % for larger tubes with an ID of 9.5 mm commonly used for sterile filtration and transport processes. Analysis of tubes with varying ID revealed a linear relationship between the decrease of phenol and the surface-to-volume ratio. m-cresol showed an even more pronounced loss in silicone tubing. Fluorinated polymers and thermoplastic elastomers were also analyzed, and no loss of phenol and m-cresol was observed. Pumping tests revealed that shear forces in peristaltic pumps led to strong particle formation in selected tubing. A strong increase in particle concentration was observed in thermoplastic elastomers, particularly in PharMed® BPT tubing. In contrast, the C-Flex® tubing demonstrated minimal particle formation. Fluorinated polymers are not compatible with peristaltic pumps, which is why they were not analyzed regarding pumpability. Although silicone tubes are not impervious to preservatives such as phenol, they did not generate particles when pumped.

The Influence of the Steam Sterilization Process on Selected Properties of Polymer Samples Produced in MEX and JMT Processes.

Polymeric materials are widely used in medical engineering, and with the dynamic development of additive manufacturing (AM) technology, increasing attention is being paid to research on the mechanical strength of composite polymer structures. At the same time, the impact of sterilization on, for example, surgical templates and the influence of the sterilization process on the geometry of these parts have not been sufficiently studied. In this work, the effect of steam sterilization on samples made of polymer materials for medical applications was presented. This research was carried out on samples with normative geometry made of polyetheretherketone (PEEK) polymers produced using the Material Extrusion (MEX) AM process and acrylic formulation (MED610) produced by Jetting Modeling Technology (JMT). These materials provide biocompatibility, which makes them suitable for potential medical applications. Steam sterilization was performed in an autoclave at temperatures of 121 °C and 134 °C. The three-point bending strength properties were determined according to ISO 178 standards. An INSTRON 5967 strength testing machine was used for those tests. Surface roughness analysis (according to ISO 21920) was performed and presented in 2D and 3D surface views using the Mountains Map Software (version 6.0).

New chamber stapes prosthesis: Effect of ionizing radiation on material and functional properties

Abstract New chamber stapes prosthesis (ChSP) is a middle-ear prosthesis intended for use in ear surgery for restoring the patient's middle ear function. As the prosthesis is an implantable medical device, it must be sterilized before use. However, possible alterations in the material and the functional properties following the sterilization process can influence the safety aspects while using the prosthesis. The purpose of this paper was to determine the effects of ionizing radiation (IR) on the physicochemical and biological properties of the new chamber prosthesis by utilizing EPR spectroscopy, mechanical testing, and cytotoxicity studies. Our research shows that the radiation treatment increases the hardness and the elastic modulus of the polymer, decreases the stiffness of the prosthesis membrane, and does not cause chemical changes in the polymers that may result in cytotoxicity. Furthermore, new ChSPs were successfully tested in preclinical in vitro tests. The test results justify the undertaking of further work, including in vivo biocompatibility tests and clinical trials, which would eventually lead to the increased use of the prosthesis in clinical practice.

Utilization Fraction of Ambulatory Hand Procedures: Cost-Reduction Through Surgical Instrument Tray Optimization.

Our objective is to evaluate the utilization fraction (UF) of surgical instruments during a commonly performed ambulatory hand surgery case as an avenue for cost reduction, increased operating room efficiency, and systems quality improvement. The total number of instruments opened at the start of the case was recorded followed by instruments being divided into those used and not used during the procedure. Total sterile processing costs were estimated at $1.56 per instrument according to data from our institution's central sterilization processing (CSP) department. Nineteen hand procedures performed by 2 surgeons were included in this study. An average of 120.1 ± 10.9 instruments were opened at the start of each case, while an average of 12.6 ± 5.4 instruments were used per case (Figure 1). This yielded an UF of 10.7% ± 4.8%. Using our internal CSP estimate, we calculated an annual cost of $16 863 to reprocess the current hand tray (Figure 2). Using literature data, this cost ranged from $5 513 to $34 484 annually. The same cost calculations were performed for the theoretical optimized tray (incorporating instruments used at least 20% of the time when opened) containing 23.2 instruments. The annual reprocessing cost of this new tray according to CSP data was $3 260, demonstrating a cost-reduction of $13 603 or 80.7% (Figure 2). Evaluation of pre- and peri-operative processes is a valuable technique to mitigate increasing healthcare costs and reduce unnecessary healthcare spending, with broad applicability to multiple surgical subspecialties and procedures.

Does Transforaminal Endoscopic Lumbar Discectomy Provide More Value than Microdiscectomy? An Application of the Operative Value Index.

A few studies have compared the value (outcomes per dollar spent) provided by transforaminal endoscopic discectomy (TED) vs microdiscectomy (MD) for lumbar disc herniations. Here, we attempt to address this gap using a novel Operative Value Index (OVI), which combines a procedure-specific patient-reported outcome with intraoperative cost data based on time-driven activity-based costing. MD (n = 95) and TED (n = 23) performed by neurosurgeons at our institution from 2017 to 2022 were retrospectively identified. Time-driven activity-based costing was applied to identify both direct and indirect costs for all cases. Individual costs were obtained by direct observation, electronic medical records, and through consulting multiple departments (including business operations, sterile processing, plant operations, and pharmacy). Oswestry Disability Index (ODI) scores were prospectively collected at baseline and 3 months after surgery. Our primary outcome of interest was the OVI, defined as the percent change in the ODI per $1000 spent intraoperatively. Generalized linear mixed model regression was performed to assess whether TED was associated with significantly different OVI as compared to MD. Similar analyses were also performed for operative times and length of stay. The average intraoperative cost of a TED was $3698, as compared to $3410 for an MD. For both procedures, this total cost was largely driven by the cost of supplies and personnel. Multivariable regression revealed that MD was associated with significantly higher OVI (β-coefficient: 7.2, P < .05) and lower operative times (β-coefficient: - 34.6 minutes, P < .01) compared with TED, with no significant differences in length of stay (P = .17). When performed by surgeons at our institution from 2017 to 2022, MD was associated with a 7% greater improvement in ODI per $1000 spent intraoperatively. Continual assessment of value over time (both for established procedures and new techniques) will become increasingly important with the emergence of value-based care.

MANEJO DE FERIDAS EM COELHO ATRAVÉS DO USO DA PELE DE TILÁPIA LIOFILIZADA

The study addresses the importance of treating skin lesions in veterinary medicine, with an emphasis on wound healing in rabbits with pododermatitis, including the use of Nile tilapia skin as a therapeutic alternative for grafting after debridement of necrotic ulcers. Skin lesions can be caused by trauma, bites or other causes, compromising vital skin functions, such as protection and defense against infections. Tilapia skin is rich in type I collagen and has been highlighted as an accessible and effective biomaterial in the treatment of wounds, stimulating cell regeneration and healing. The work reports the case of a rabbit, named Paçoca, diagnosed with ulcerative pododermatitis in the left pelvic limb, a chronic condition that can lead to serious complications. The clinical signs of the pathology are pain, abdominal and limb alopecia, edema, ulcerative lesions, loss of joint mobility with the presence of osteolytic reactions. Pododermatitis in rabbits is often related to factors such as cage floor quality, excess weight, and sedentary lifestyle. The rabbit’s treatment included debridement of necrotic tissue and the application of tilapia skin as a graft. The tilapia skin was prepared through a rigorous sterilization and preservation process, involving immersion in specific solutions and the application of antibiotics. The use of this skin as an occlusive dressing helped stimulate growth factors essential for skin regeneration, such as fibroblasts and keratinocytes. The use of this biomaterial proved effective in the treatment of wounds with significant tissue loss, avoiding the need for sutures and promoting healing through the formation of new tissue. Postoperative follow-up included the use of antibiotics and anti-inflammatories, and treatment with tilapia skin contributed to the successful recovery. The study highlights the effectiveness of the biomaterial in the management of skin wounds in rabbits, especially in the recovery of lesions caused by ulcerative pododermatitis. Therefore, after treatment, the rabbit presented good healing, the wound evolved positively, with formation of granulation tissue and epithelialization.

Sensitive HPLC Method to Support Pre-formulation Studies and to Determine Critical Quality Attributes of Therapeutic Contact Lenses Containing Dorzolamide Hydrochloride

Background: Dorzolamide hydrochloride (DRZ) is a carbonic anhydrase inhibitor used to treat glaucoma and ocular hypertension. Drug-eluting contact lenses, such as Acuvue Theravision ™ with Ketotifen, offer improved drug delivery and reduced side effects compared to eye drops. Drug-loaded nanoparticle-loaded contact lenses can sustain drug release and enhance comfort for extended wear. Objective: High buffer concentration and low pH increase the risk of damage to silica-bonded columns. Therapeutic contact lenses face challenges related to critical lens parameters, including the estimation of drug incorporation and release due to interference of lens matrix leaching. There is currently no analytical method available for estimating DRZ in contact lenses. Method: The HPLC method, which was developed and validated using ICH Q2 (R1) criteria, used a C18 column (250 mm × 4.6 mm, 5 μm) as a stationary phase and methanol:water (70:30 v/v) as the mobile phase. The detecting wavelength was 253 nm. Moreover, to support the efficiency of the developed method, the marketed formulation of DRZ eye drops, drug purity, and loading in contact lenses were analysed. The method was also employed to determine the Critical Quality Attributes (CQAs) of therapeutic contact lenses and drug release and drug leaching during the sterilization process. Result: The developed HPLC method shows Rt for DRZ at 2.881 minutes with good linearity (r2 &gt; 0.998) between 2-32μg/mL, precision (RSD &lt; 2%), accuracy (Recovery &gt; 99.5%), sensitivity, and specificity for quantifying DRZ in marketed formulations and therapeutic contact lenses. The developed method is devoid of any buffer or modifier in the mobile phase, making it safer for the stationary phase. This method mitigates the interference of lens matrix leaching, which induces an overestimation of DRZ. All the result for therapeutic contact lenses was found to be closely aligned with theoretically expected results, confirming the reliability of the developed HPLC method for therapeutic contact lenses. Conclusion: This method is specific, accurate, and precise for quantifying DRZ in commercial formulations and newly developed therapeutic contact lenses. It effectively evaluates the critical quality attributes of these lenses, demonstrating their reliability for assessing their performance and ensuring quality in therapeutic applications.

What is the True Cost of Motion Preservation? A Time-Driven Activity-Based Cost Analysis of Anterior Cervical Discectomy and Fusion versus Disc Replacement

Total disc replacement (TDR) has become a viable alternative to anterior cervical discectomy and fusion (ACDF) for select patients. Although most comparative studies have assessed outcomes, cost differences remain largely uninvestigated. This information is critical as we move towards value-based reimbursement. To address this knowledge gap, we used time-driven activity-based costing to compare total intraoperative costs between the 2 procedures. Total cost was divided into direct (personnel and supply cost) and indirect costs (administrative and overhead costs). Individual costs were determined through direct observation, electronic medical records, and through querying multiple departments (including business operations, sterile processing, plant operations, and pharmacy). Timestamps for all involved personnel and material resources were documented, in conjunction with process mapping of the intraoperative period. Total intraoperative costs were estimated for all ACDFs (n= 810) and TDRs (n= 54) from 2017 to 2022. Regression analyses were performed to identify factors associated with total cost. A total of 810 and 54 patients underwent 1-and 2-level ACDFs and TDRs, respectively. The average total intraoperative cost for an ACDF was $6776+/- $2,808, compared to $12,026+/- $4235 for TDR. Supply cost accounted for the majority of total cost for both procedures ($4173+/- $2225 for ACDF and $9532+/- $4010 for TDR). On multivariable linear regression analysis, TDR was associated with roughly $3885 of additional cost compared to ACDF (P < 0.001), as well as $4072 in additional supply cost (P < 0.001), most of which was driven by the higher cost of implants (P < 0.001). Time-driven activity-based costing is a highly useful methodology for estimating differences in true costs between procedures and determining cost drivers. TDRs were associated with an additional $3885 of total intraoperative cost as compared to ACDFs, the majority of which was driven by the cost of implants.

Refinement of the in vitro propagation process of Petunia (Petunia hybrida) plant

Petunia (Petunia hybrida) is currently one of the most favored ornamental potted flowers. Tissue culture-based propagation has proven to be effective in terms of multiplication rates and consistent seedling quality, meeting the demand for Purple Petunia varieties. In this study, Sodium hypochlorite (NaOCl) with various culture media [Murashige and Skoog (MS), ½ MS, and Knudson C] and growth regulators [6-benzyladenine (BA), Indole 3-butyric acid (IBA), and Naphthaleneacetic acid (NAA)] were utilized to determine the appropriate concentrations and durations for sample sterilization, shoot multiplication, and root induction processes of Purple Petunia. Evaluation criteria for in vitro Purple Petunia included parameters, such as survival rate, contamination rate, dead samples, number of shoots, shoot height, number of roots, and root length. The results indicated that stem sample sterilization at a 5% NaOCl concentration for 10 min yielded the highest survival rate (70.7%) at 14 days post-culture initiation. Purple Petunia stem samples, when cultured in MS medium supplemented with 0.5 mg/L BA combined with 0.1 mg/L IBA, demonstrated the most efficient shoot multiplication with a multiplication rate of 26.9, a shoot weight of 3.6 g, a leaf/shoot ratio of 4.6, and a shoot height of 3.0 cm. The MS medium supplemented with 0.1 mg/L NAA was found to be optimal for root induction, resulting in the highest number of roots at 32.1 roots/plant and a root length of 7.0 cm. Briefly, this research provided fundamental insights into the in vitro propagation process of disease-free Purple Petunia multiplication.

A two-stage hybrid flow-shop formulation for sterilization processes in hospitals

Sterile processing is a critical secondary process and a major cost factor in the processing, acquisition, and storage of costly medical devices. This article aims to improve the performance of sterile processing by developing, implementing, and evaluating a dispatching rule-based algorithm to reduce the time medical devices spend in the central sterile supply department using a two-stage hybrid flow-shop formulation. The algorithm combines dispatching rules with stage decomposition and compatibility conditions. A genetic algorithm is designed to benchmark the performance in addition to an analytic bound. Real-world data from a large German hospital were used to test the effectiveness of the heuristics. The case study demonstrated the practical implications of the approach, leading to a reduction in the time medical devices spend in the system and improved utilization of washer-disinfector machines and sterilizers. It also highlighted the importance of aligning machine capacity with demand and the potential trade-offs associated with batch processing decisions. Our approach can contribute to substantial operational cost savings and efficiency gains, offering significant benefits to decision makers at both the operational and tactical levels.

Modification of surface topographies to inhibit candida biofilm formation.

The rise of infections associated with indwelling medical devices is a growing concern, often complicated by biofilm formation leading to persistent infections. This study investigates a novel approach to prevent Candida albicans attachment on the surface by altering surface topography. The research focuses on two distinct surface topographies: symmetry (squares) and non-symmetry (lines), created through a direct laser photolithography process on a Cyclic olefin copolymer (COC) surface. The wettability of these patterned surfaces was then examined immediately after fabrication and plasma treatment to mimic the sterilization process of indwelling devices through UV plasma. The results reveal directional wettability in the line pattern and size-dependent wettability in both square and line patterns. Candida albicans were cultured on these surfaces to assess the efficacy of the topography in preventing biofilm formation. The study demonstrates that symmetry and non-symmetry pattern topography inhibit biofilm formation, providing a promising strategy for mitigating Candida-associated infections on medical devices. The research sheds light on the potential of surface modification techniques to enhance the biocompatibility of medical devices and reduce the risk of biofilm-related infections.

Postoperative ileus-Immune mechanisms and potential therapeutic interventions.

Postoperative ileus (POI) is a condition marked by a temporary suppression of gastrointestinal motility following abdominal surgery. The mechanism of POI encompasses various factors and is characterized by two phases: the early neurogenic phase involving both adrenergic and non-adrenergic neural pathways; the later immune-mediated phase is characterized by a sterile inflammatory response that lasts several days. Activation of muscularis macrophages triggers a sterile inflammatory process that results in dysfunction of the enteric nervous system (ENS) and a reversible inhibition of gastrointestinal motility. In this minireview, recent insights in the pathophysiological mechanisms underlying POI and potential new therapeutic strategies are described.

Estimation of gamma radiation effects on the polypropylene (PP) films at various doses

Medical polypropylene (PP) is exposed to ionizing radiation during the sterilization process before its use for medical purposes. Herein, the raw and manufactured PP were prepared as polymeric films with the same specifications. Then, raw and manufactured PP were irradiated by different doses of gamma rays in the air to discover the gamma radiation effects on the prepared films. The gamma doses were 25, 50, 75, 100, and 200 kGy. The irradiated raw and manufactured PP were characterized by different analytical techniques such as Electron Spin Resonance Spectrometer (ESR), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and mechanical properties. The FTIR study indicated the presence of a new band at a low gamma dose for both cases. The crystallinity percentages of both raw and manufactured PP gradually reduced when the gamma doses increased. The thermal stability of films decreased by increasing the gamma doses. Raising the gamma dosages resulted in a decrease in the mechanical characteristics of raw PP and manufactured PP such as elongation @ break, elastic modulus, and tensile strength.

Pengendalian Kualitas pada Industri Kerajinan Sarung Tangan dengan Metode Six Sigma dan FMEA pada CV. XYZ

XYZ is a company that produces gloves. Due to the resulting defects such as vague logos, slanted stitching, mold and loose stitching, the company needs to make quality improvements so that defects become 0%. The aim of this research is to carry out quality control using the Six Sigma and FMEA methods to determine the sigma value and determine the causes of defects and make recommendations for improvements to the highest defects. From the results of Six Sigma calculations, a sigma level of 3.6 was obtained, which means that it is sufficient and 197,300 defects can occur on a production scale of one million. The capability results with an average value of 1.15 indicate that it is only quite reliable on a scale of 1-2. FMEA shows the highest cause of failure is sewing machine jams which can cause skewed stitches. The recommended control plan is to carry out routine weekly machine maintenance. Common factors causing defects are lack of regular maintenance on production machines, worker negligence, worker fatigue due to hot weather, lack of strict supervision of workers during the production process, less skilled workers and humid air temperatures resulting in moldy gloves. Proposed improvements in overcoming defects include carrying out routine maintenance on all machines, carrying out strict supervision of workers, implementing SOPs with strict supervision, adding air conditioning facilities, and adding a sterilization process for finished glove products. Keywords: DMAIC, FMEA, Six Sigma