48 research outputs found

    Extraction of cellulose from waste papers for the preparation of cellulose graft-poly (acrylamide) for superabsorbent

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    This article reports the use of wastepaper pulp as a direct source of cellulose for producing superabsorbent polymer. The white papers obtained from the offices in Adamson University were cut into 1 inch square pieces and drenched with distilled water and borax. This procedure was done couple of times to achieve a pH of 8 and consistency of 1%-2%. Commercial cotton was used as control to compare and differentiate the properties and structures with the superabsorbent polymer (SAP). Various trials have shown the value of 60 acrylamide beads to produce SAP with optimum performance. FTIR analysis shows properties that are characteristics of cellulose-based SAP. In the present investigation, the influence of temperature, effect in varying salt concentrations, swelling rate and water retention at constant temperature were evaluated. The SAP’s maximum swelling capacity ranges from 0.6561 g to 1.0638 g regardless of the amount of NaCl used. The swelling rate of the SAP proves that it gets heavier with time. Hence, it can be implied that the ability of the SAP to retain water is good. The temperature dependence data revealed the sorption process was favorable at higher temperature. The SAP will absorb the highest amount of solution at 500C given that the solution is pure

    Systematic Review and Meta-Analysis of Unconventional Perfusion Flaps in Clinical Practice

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    Background: Although unconventional perfusion flaps have been in clinical use since 1975, many surgeons are still deterred from using them, because of some reports of high necrosis rates. Methods: The authors performed a systematic review and meta-analysis of all articles written in English, French, German, Spanish, and Portuguese on the clinical use of unconventional perfusion flaps and indexed to PubMed from 1975 until July 15, 2015. Results: A total of 134 studies and 1445 patients were analyzed. The estimated survival rate of unconventional perfusion flaps was 89.5 percent (95 percent CI, 87.3 to 91.3 percent; p < 0.001). Ninety-two percent of unconventional perfusion flaps (95 percent CI, 89.9 to 93.7 percent; p < 0.001) presented complete or nearly complete survival. Most defects mandating unconventional perfusion flap reconstruction were caused by trauma (63.6 percent), especially of the hand and fingers (75.1 percent). The main complication of all types of flaps was a variable degree of necrosis (7.5 percent of all unconventional perfusion flaps presented marginal necrosis; 9.2 percent and 5.5 percent had significant and complete necrosis, respectively). There was a positive correlation between the rate of postoperative infection and the need for a new flap (Pearson coefficient, 0.405; p = 0.001). Flaps used to reconstruct the upper limb showed better survival than those transferred to the head and neck or to the lower limb (p < 0.001). Conclusion: Unconventional perfusion flaps show high survival rates and should probably be used more liberally, particularly in the realm of upper limb reconstruction. Clinical question/level of evidence: Therapeutic, V.info:eu-repo/semantics/publishedVersio

    Free Gracilis Muscle Flap for Sarcoma Reconstruction: 19 Years of Clinical Experience

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    Background. Sarcoma treatment necessitates high-dose chemoradiation therapy and wide surgical margins that create wounds that are difficult to reconstruct. Many techniques have been developed to cover these defects, originating with muscle flaps such as the rectus abdominis and latissimus dorsi. The gracilis flap, which is best known in contemporary practice as a microneurovascular flap for functional reconstructions, is not usually considered a robust option for reconstruction after sarcoma extirpation. Methods. We reviewed records of 22 patients (9 women) at our institution who underwent reconstructive surgery after sarcoma extirpation using gracilis flaps for soft-tissue coverage from 1998 to 2017. Neurotized gracilis flaps were excluded. The mean patient age was 51 years (range, 18–85 years), and mean length of follow-up was 53 months (range, 9–156 months). Patients had 7 tumor types, with fibrosarcomas and undifferentiated tumors being most common. There were 23 defects (mean size, 118 cm2 (range, 54–200 cm2)). Defects were located most commonly in the foot and leg (n=9 each), upper extremity (n=4), and head and neck (n=1). The primary outcome was the flap success rate. Secondary outcomes were rates of major complications (unplanned reoperations, infections requiring intravenous antibiotics, and amputations); minor complications (superficial infections, partial skin-graft loss, partial flap necrosis, fluid collections treated in the office, and cosmetic reoperations); and sarcoma recurrence. Results. Twenty-one flaps (91%) survived. Six patients (27%) experienced a major complication, and 12 patients (54%) experienced a minor complication. There were 2 amputations, for a limb salvage rate of 91%. Conclusions. This series shows that the gracilis is well suited to covering large, compromised wounds across diverse anatomic features, which are the hallmark of sarcoma resections. The high rate of limb salvage and minimal donor-site morbidity further support the use of this flap as a first-line option for sarcoma reconstruction

    Give your patients a hand

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