Sustainable Alkaline Hydrolysis of Polyester Fabric at Low Temperature

High crystallinity leads to low hydrophilicity of fabric made of (poly(ethylene terephthalate)) fibers (PET) causing problems in finishing, washing, and dyeing processes. To improve these properties, the surface of PET fibers is usually modified by hydrolysis. Alkaline hydrolysis is a conventional process usually performed at a temperature higher than 100 °C for more than 1 h. However, the use of strong alkali and high processing temperatures (>100 °C) can lead to fabric damage and a negative impact on the environment. Therefore, in this paper, the possibility of hydrolysis of the PET fibers in the fabric in a sustainable, energy-efficient process was researched. The influence of low temperature (60–100 °C) and an accelerator (a cationic surfactant HDTMAC) to PET alkaline hydrolysis was studied through weight loss, the loss in breaking force, and fiber morphology. The kinetics of PET dissolution in 1.5 mol cm⁻³ NaOH at low temperature with and without the addition of HDTMAC was determined and the activation energy was calculated according to the theoretical model. It has been confirmed that PET hydrolysis can be carried out in 1.5 mol cm⁻³ NaOH with the addition of HDTMAC as an accelerator at 80 °C for 10 min. This process is more economically and energetically acceptable than the conventional process, and is therefore more sustainable.     

Acupuncture of specific points influences cortical auditory evoked potentials--a volunteer crossover study

Specificity of acupoints remains a crucial question in acupuncture research. The aim was to investigate whether acupuncture of specific points influences the Cortical Auditory Evoked Potentials (CAEP). Ten healthy volunteers were enrolled in this study according to inclusion criteria. One of 4 acupoints: TH3, GB43 (both claimed as specific for auditory system by Traditional Chinese Medicine) and non-specific points H7 and ST44, was stimulated during one session. Each volunteer received 4 sessions of acupuncture with an interval of 1 week between the sessions. The latencies and amplitudes of CAEP were registered before and after the acupuncture during each session. The mean peak latencies of P2 component decreased after stimulation of TH3 by 11 ms and GB43 by 14 ms whereas the peak latencies of N2 component increased after stimulation of TH3 by 9 ms and GB43 by 4 ms compared to baseline values (p<0.05). The stimulation of H7 and ST44 did not produce any changes. These findings confirm the specificity of acupuncture points TH3 and GB43 in relation to auditory system.     

A radiofrequency-assisted minimal blood loss liver parenchyma dissection technique

BACKGROUND/AIMS: Intraoperative blood loss is still a major concern for surgeons operating on the liver since it is associated with a significantly higher rate of postoperative complications and shorter long-term survival. An original radiofrequency (RF)-assisted minimal blood loss technique for transecting liver parenchyma is presented. METHODS: In a prospective study, starting November 2001 and ending December 2005, a total of 90 RF-assisted liver resections were done. Pre-cut coagulative desiccation was produced by the Cool-tip (Valleylab, Tyco) water-cooled, single, RF tumor ablation electrode connected to a 480-kHz 200 W generator (Valleylab Cool-tip RF System). Vascular occlusion techniques and low central venous pressure anesthesia were not used. RESULTS: Only 14 (15.5%) patients received blood transfusion (mean transfused blood volume 397 ml; mode 310 ml) and 10 of 14 patients received <310 ml of blood. There was no statistical difference between the patients who underwent major and minor liver resection in frequency of blood transfusion. Blood loss was associated with dense adhesions and difficult liver mobilization and not with liver transection. CONCLUSION: The 'sequential coagulate-cut' RF-assisted liver resection technique is a safe liver transection technique associated with minimal blood loss and it has facilitated tissue-sparing liver resection.     

Popliteal traumatic arteriovenous fistulas

BACKGROUND: The purpose of this report is to analyze the clinical presentation, diagnosis, and outcome of surgical treatment in patients with popliteal arteriovenous fistulas (AVFs) in order to make trauma surgeons aware of the various issues patients with popliteal AVFs might present. METHODS: From 1991 to 2000, 49 patients were treated for traumatic AVF. Among these patients, seven suffered from popliteal AVF of various durations. The patients were men and ranged in age from 17 to 27 years, with a mean age of 22.4 years. The time from injury to admission to our institutions varied from 5 days to 2 years. A diagnosis of popliteal AVF was made after clinical examinations revealed thrill and bruit over the injury sites. The diagnosis was confirmed in four of the patients after they underwent angiography. Patients with long-standing popliteal AVF underwent cardiology examinations to check for signs of heart failure. All patients with popliteal AVF received surgical treatment. Five patients had major blood vessels reconstructed, one patient had a minor blood vessel ligated, and another patient had a minor blood vessel reconstructed. RESULTS: Five of the seven patients experienced no postoperative difficulties. No serious heart failure occurred; however, there were signs of cardiac overload in three of the five patients. The two remaining patients of the seven underwent leg amputations. However, one of the two patients had a gangrenous foot at admission to our institution, and vascular reconstruction on the other patient was unsuccessful. For all seven patients, the average hospital stay in the vascular surgery department was 16.2 days and the follow-up ranged from 2 to 44 months, with a mean of 21.5 months. CONCLUSION: Trauma of the popliteal space requires special attention, since blood vessel injuries in that zone might result in serious complications. Popliteal traumatic AVFs result in a high rate of leg amputation and long-standing fistulas produce cardiac overload. The presence of thrill and bruit over the injury site should alert the examiner to consider the existence of AVF. Angiography is a reliable diagnostic tool, and should be used in all vitally stable patients. Surgical or nonsurgical closure of AVF will prevent local and systemic complications that might be irreversible in long-standing fistulas.     

Necrotizing fasciitis caused by group A streptococcus

The first case of the confirmed necrotizing fasciitis caused by Group A Streptococcus in Yugoslavia was presented. Male patient, aged 28, in good health, suddenly developed symptoms and signs of severe infective syndrome and intensive pain in the axillary region. Parenteral antibiotic, substitutional and supportive therapy was conducted along with the radical surgical excision of the necrotizing tissue. The patient did not develop streptococcal toxic shock syndrome thanks to the early established diagnosis and timely applied aggressive treatment. He was released from the hospital as completely cured two months after the admission.     

Recurrent episodes of focal cerebral ischemia in a female patient with mitral valve prolapse and migraine headache

Migraine is episodic, paroxysmal disorder where the headache represents the central symptom and is followed with different combinations of neurologic, gastrointestinal and vegetative changes. Not until the diagnostic procedures were developed, ischemic lesions were verified even in the patients with ordinary migraine. This is a report of a patient with migraine headache, followed twice by verified episodes of temporary ischemic attacks and verified focal ischemic lesion of cerebral parenchyma. The mitral valve prolapse was also detected. This all imposed the administration of combined prophylactic antimigrainous and anticoagulant therapy as an imperative because of the risk of the development of repeated ischemia of cerebral tissue. This association also confirmed an opinion that migraine is a wider disorder with the dominant dysfunction of limbic system.     

Genome-wide loss of heterozygosity analysis of chemically induced rat hepatocellular carcinomas reveals elevated frequency of allelic imbalances on chromosomes 1, 6, 8, 11, 15, 17, and 20

Neoplastic development is a multistep process that involves the stochastic accumulation of heritable genetic alterations in proto-oncogenes, DNA repair genes, and tumor suppressor genes. Loss of heterozygosity (LOH) analysis has been used successfully to identify the genetic determinants of neoplastic development, including tumor suppressor genes, in several species and organs but not in the rat liver. We report the results of a sensitive genome-wide LOH analysis of rat hepatocellular carcinomas (HCCs). Heterozygous rats (Wistar-Furth x Fisher 344) were subjected to an Initiation-Promotion-Progression (IPP) protocol of hepatocarcinogenesis. Two weeks after initiation (by partial hepatectomy, 10 mg/kg diethylnitrosamine), the rats were placed on a diet containing 0.05% phenobarbital (PB). After 24 wk of PB promotion, the rats received either 100 or 1 50 mg/kg ethylnitrosourea. Hepatocellular tumors were resected after a total of 76wk of PB promotion. LOH analysis was completed on 26 HCCs by using 60 microsatellite markers covering all 20 rat autosomes and chromosome X. While 85% of the HCCs had one or more allelic imbalances, the average HCC had 3.3 allelic imbalances (range 0-9). A conditional hypothesis-testing method called the Hot-Cold model was used to determine the location of statistically significant elevations in the frequency of allelic imbalances. Elevated allelic imbalances were observed on chromosomes 1q, 6, 8, 11, 15, 17, and 20p. Together, these allelic imbalances suggest that the retinoblastoma and insulin-like growth factor genes as well as the resistance to chemical carcinogenesis (rcc) locus may be involved in HCC development in the rat but that LOH of the p53 gene is not. The elevated rate of allelic imbalances on chromosomes 8,11, and 17 may indicate the location of undiscovered tumor suppressor genes important to neoplastic development in rat liver. Microdissection-based LOH analysis of HCC revealed that contamination of non-neoplastic and nonhepatocellular tissue was not masking LOH in the whole-tumor analysis. There were no statistically significant differences in the frequency of allelic imbalances between HCC of any differentiation state (histological grade). To the degree that it does not reflect differences in etiological factors, the absence of allelic imbalances in chromosomal regions containing the p53 and mamose-6-phosphate/insulin-like growth factor II receptor tumor suppressor genes and the generally low frequency of allelic imbalances in these tumors, suggests that LOH and allelic imbalances play a less significant role in the molecular pathogenesis of HCC in rats than humans.     

Usefulness of distraction osteogenesis in the treatment of knee arthrosis]

AIMS: The purpose of this study is the assessment of efficiency of distraction osteogenesis (DO) as a method of operative treatment of knee arthrosis with co-existent varus deformity. MATERIAL AND METHODS: Authors undertook an attempt of evaluation of results of tibial corticotomy in 21 patients (25 operated knee joints) treated in Orthopaedic Clinic of Wroclaw Medical University in years 1995-2001, with the use of circular, external Ilizarov's fixator. All the operated patients underwent corticotomy of proximal tibial metaphysis followed by slow axis correction and bone regenerate formation started at 7th postoperative day. In orthopaedic examination functional evaluation of knee joint with modified point scale according to Ranawat (HSS-score) there were taken into account. In rentgenometric examination the limbs axis in the frontal plane and joint space morphology according to Ahlback were evaluated. RESULTS: The results in our group of patients were very encouraging. Accordingly to Ranawat scale, in majority of patients assessed before the treatment as poor and fair moved to group assessed as fair and good and even excellent. We observed decelerated regenerate formation and remodeling probably caused by advanced age of patients in 6 cases. In 3 cases persistent lose of entire correction was observed. CONCLUSIONS: In author's opinion DO as a method of operative treatment of unicompartmental knee arthrosis could be advocated as alternative method to traditional tibial osteotomy considering its biological effect stimulating regeneration of all tissues including cartilage even in advanced unicompartmental arthrosis.