Development of Nano-Sized Copper-Deposited Antimicrobial Air Filters Using a Mixed Melt-Blown Process.

Air purification devices, such as air purifiers, provide fresh air by filtering out airborne pollutants, dust, and other harmful substances using various filter systems. While air filters are generally effective in filtering pollutants such as dust, they encounter a challenge when filtering harmful microorganisms such as mites, bacteria, mold, and viruses. These microorganisms, which are present in public transport and public indoor spaces, tend to proliferate on the surface of the filter media, eventually reintroducing themselves into the air or causing unpleasant odors. To address this issue, herein, copper particles were prepared as one masterbatch and deposited on polypropylene (PP) pellets through plasma vacuum deposition to effectively filter dust and microorganisms and prevent their growth on the surface of the filter media. After adding 3-10 wt.% of the masterbatch to conventional PP pellets to fabricate a filter media, the distribution of copper on the surface of the filter media was observed through a scanning electron microscope. To verify the safety and effectiveness of the antimicrobial material, the filter media containing antimicrobial particles was tested using Escherichia coli (E. coli) and Staphylococcus aureus through a filter emission test.

Influence of posteromedial corner injuries on clinical outcome and second-look arthroscopic findings after allograft transtibial anterior cruciate ligament reconstruction.

BACKGROUND: The purpose of this study was to evaluate the influence of posterior medial corner (PMC) injuries on clinical outcome and second-look arthroscopic findings after anterior cruciate ligament (ACL) reconstruction. METHODS: Seventy-eight consecutive patients underwent a second-look arthroscopic surgery after ACL reconstruction and magnetic resonance imaging (MRI) examination of the PMC. The patients were divided into a PMC intact group (n = 42) and a PMC injured group (n = 36). The stability and clinical outcomes were evaluated using the Lachman test, pivot-shift test, a KT-2000 arthrometer, and the Lysholm knee scoring scale. Graft tension and synovial coverage were evaluated in second-look arthroscopy. RESULTS: The clinical function showed no significant differences regarding PMC injury. Although the graft tendon tension revealed no significant differences (p = 0.141), the second-look arthroscopic findings indicated that the PMC intact group showed better synovial coverage compared to the PMC injured group (p = 0.012). CONCLUSION: Patients who injured the PMC had poor synovial coverage as assessed by second-look arthroscopic findings after transtibial ACL reconstruction, even though clinical outcomes and stability showed no significant differences.

Validation and Application of the Mass Balance Model To Determine the Effectiveness of Portable Air Purifiers in Removing Ultrafine and Submicrometer Particles in an Apartment.

We validated the use of the mass balance model to determine the effectiveness of portable air purifiers in removing ultrafine (<0.10 µm) and submicrometer particles (0.10-0.53 µm) in an apartment. We evaluated two identical portable air purifiers, equipped with high efficiency particulate air filters, for their performance under three different air flow settings and three target air exchange rates: 0.60, 0.90, and 1.20 h(-1). We subsequently used a mixed effects model to estimate the slope between the measured and modeled effectiveness by particle size. Our study showed that effectiveness was highly particle size-dependent. For example, at the lowest target air exchange rate, it ranged from 0.33 to 0.56, 0.51 to 0.75, and 0.60 to 0.81 for the three air purifier flow settings, respectively. Our findings suggested that filtration was the dominant removal mechanism for submicrometer particles, whereas deposition could play a more important role in ultrafine particle removal. We found reasonable agreement between measured and modeled effectiveness with size-resolved slopes ranging from 1.11 ± 0.06 to 1.25 ± 0.07 (mean ± SE), except for particles <35 nm. Our study design can be applied to investigate the performances of other portable air purifiers as well as the influences of various parameters on effectiveness in different residential settings.

Development of an activated carbon filter to remove NO2 and HONO in indoor air.

To obtain the optimum removal efficiency of NO2 and HONO by coated activated carbon (ACs), the influencing factors, including the loading rate, metal and non-metal precursors, and mixture ratios, were investigated. The NOx removal efficiency (RE) for K, with the same loading (1.0 wt.%), was generally higher than for those loaded with Cu or Mn. The RE of NO2 was also higher when KOH was used as the K precursor, compared to other K precursors (KI, KNO3, and KMnO4). In addition, the REs by the ACs loaded with K were approximately 38-55% higher than those by uncoated ACs. Overall, the REs (above 95%) of HONO and NOx with 3% KOH were the highest of the coated AC filters that were tested. Additionally, the REs of NOx and HONO using a mixing ratio of 6 (2.5% PABA (p-aminobenzoic acid)+6% H3PO4):4 (3% KOH) were the highest of all the coatings tested (both metal and non-metal). The results of this study show that AC loaded with various coatings has the potential to effectively reduce NO2 and HONO levels in indoor air.

Arthroscopic management of chronic unstable scaphoid nonunions: effects on restoration of carpal alignment and recovery of wrist function.

PURPOSE: The purpose of this study was to assess the effects of arthroscopically assisted reduction and osteosynthesis on restoration of carpal alignment and recovery of clinical wrist function in patients with unstable scaphoid nonunion. METHODS: Thirty-six patients who underwent arthroscopically assisted osteosynthesis with or without bone grafting for unstable scaphoid nonunion between July 2006 and January 2012 were enrolled. The average time from injury to surgery was 51 ± 78.3 months. Radiographic and clinical evaluations were assessed on preoperative and postoperative days, and follow-up evaluation took place at a minimum of 24 months. RESULTS: Union was achieved in 86% (31 of 36) of patients at a mean of 11 ± 2.7 weeks. Scaphoid axial length (SAL), lateral intrascaphoid angle (ISA), scapholunate angle (SLA), and reversed carpal height ratio (CHR) was significantly improved after surgery, and those correction ratios averaged 66% ± 46.8%, 74% ± 58.2%, 81% ± 59.8%%, and 94% ± 46%, respectively. The range of wrist motion was unchanged after surgery, but the grip strength improved from 74% ± 22.1% preoperatively to 89% ± 13.7% postoperatively compared with the contralateral side (P = .042). Mean Disabilities of the Arm, Shoulder, and Hand (DASH) and Patient-Related Wrist Evaluation (PRWE) scores improved significantly (P < .001) from 44 and 51 preoperatively to 13 and 23 postoperatively, respectively. The radiological parameters of the scaphoid and carpal alignment in patients who achieved bony union did not correlate with clinical wrist function. CONCLUSIONS: Arthroscopic reduction and osteosynthesis of chronic unstable scaphoid nonunion is limited for restoration of normal carpal alignment but has positive effects on the recovery of clinical wrist function. LEVEL OF EVIDENCE: Level IV, therapeutic case series.