Simultaneous removal of brominated and chlorinated species during the production of oils by e-waste plastics catalytic hydropyrolysis

The production of added-value chemicals via pyrolysis of plastic wastes, such as those from electrical and electronic equipment (WEEE), needs addressing their usual contamination with halogens (mainly Br and Cl). This work compares the conversion via pyrolysis and hydropyrolysis of a real WEEE plastic, having a complex composition, in two different reactor configurations: down-flow (DF) and up-flow (UF). Likewise, the effects of incorporating a Pd/Al2O3 catalyst and using two different pressures (1 and 6 bar) have been assessed. With the DF mode, pyrolysis at 1 bar leads to an oil yield above 80 wt% and a total halogen content of about 600 ppm (vs 1600 ppm in the water-washed WEEE plastic). Under DF catalytic hydropyrolysis at 6 bar, this high oil yield is maintained while its dehalogenation degree is improved (142 ppm). Operating with the up-flow configuration, under 6 bar and H2 presence, leads to some reduction in the oil yield (about 70 wt%) but significantly decreases the oil halogen content (55 ppm Cl and total elimination of Br). These results have been related to the slower pyrolysis and longer residence time in the thermal zone of the UF configuration, which favours the halogen-trapping effect of the char fraction, and the pressure-enhanced hydrodehalogenation activity of the catalyst. This study highlights the environmental benefits of the proposed process, emphasizing the lower halogen content in the resulting oils and promoting a more sustainable approach to plastic waste valorisation.

Multi-electrolyte disturbance and supplementation in severely malnourished hospitalized adolescents with restrictive eating disorders

BACKGROUND

This study describes the prevalence of hypophosphatemia, hypokalemia, and/or hypomagnesemia and resulting electrolyte supplementation during refeeding in severely malnourished youths hospitalized for restrictive eating disorders.

METHODS

Hospitalized patients between 11-26y (N = 81) at < 75% treatment goal weight (TGW) were assessed through retrospective chart review. Outcomes were compared between participants < 70% TGW and those 70-75% TGW. Nutritional rehabilitation started at 1750 kcals/day and advanced by 500 kcal every other day until target intake was achieved. Associations between %TGW on admission; hypophosphatemia, hypokalemia, and/or hypomagnesemia; and electrolyte supplementation were examined.

RESULTS

Of the 24 (29.6%) participants with hypophosphatemia, hypokalemia, and/or hypomagnesemia, 7 (8.6%) received supplementation; the remainder corrected without supplementation. Participants < 70% TGW did not differ from those 70-75% TGW on rates of these conditions or need for supplementation.

CONCLUSIONS

Hospital-based nutritional rehabilitation did not confer increased rates of hypophosphatemia, hypokalemia, and/or hypomagnesemia or need for electrolyte supplementation in patients < 70% TGW compared to those 70-75% TGW. While additional research is needed to establish clinical practice guidelines on electrolyte management in this population, our findings suggest that nutritional rehabilitation may be reasonably undertaken without prophylactic electrolyte supplementation, even in patients < 70% TGW.

Upgrading of solid recovered fuel (SRF) by dechlorination and catalytic pyrolysis over nanocrystalline ZSM-5 zeolite

Globally increasing concern related to municipal solid waste generation is encouraging research efforts on developing alternative routes to valorize mixed refused wastes. In this way, catalytic pyrolysis is emerging as an interesting and efficient technology due to its great flexibility in terms of feedstock. In the current work, upgrading of a Solid Recovered Fuel (SRF) has been investigated by catalytic pyrolysis over nanocrystalline ZSM-5 zeolite (n-ZSM-5), paying special attention to dechlorination effects due to the high Cl content of the raw waste. Thus, pretreatment of the SRF by water washing and mild thermal processing allows for a significant reduction of the Cl concentration. Regarding the catalytic pyrolysis step, the best conditions correspond with a temperature of 400 °C in the catalyst bed and 0.50 catalyst/SRF mass ratio, which lead to ca. 30 wt% oil yield (rich in aromatic hydrocarbons) together with about 40 wt% gas yield (rich in C3-C4 olefins). Accordingly, these products could find use as raw chemicals or for the production of advanced fuels. In addition, zeolite reutilization has been tested for several cycles, denoting a progressive modification of the products distribution because of coke deposition. However, an almost total recovery of the n-ZSM-5 zeolite catalytic performance is achieved after regeneration by air calcination, affording the production of an oil fraction with a Cl content as low as 40 ppm.

Synthesis of Dendritic ZSM-5 Zeolite through Micellar Templating Controlled by the Amphiphilic Organosilane Chain Length

The synthesis of ZSM-5 zeolites by hydrothermal crystallization of protozeolitic nanounits functionalized with amphiphilic organosilanes of different chain length (Cn-N(CH3)2-(CH2)3-Si-(OCH3)3, n = 10, 14, 18 and 22) has been investigated. Well-developed dendritic nanoarchitectures were achieved when using C14 and C18 organosilanes, exhibiting a radial and branched pattern of zeolitic nanounits aggregates. In contrast, although C10 and C22 organosilanes led to materials with hierarchical porosity, they lack of dendritic features. These differences have been linked to the formation of an amorphous mesophase at the gel preparation stage for the C14 and C18 samples, in which the surfactant micelles are covalently connected with the protozeolitic nanounits through siloxane bonds. The presence of the dendritic nanostructure positively impacts both the textural and catalytic properties of ZSM-5 zeolite. Thus, ZSM-5 (C14) and ZSM-5 (C18) samples exhibit the largest contribution of mesoporosity in terms of both surface area and pore volume. On the other hand, when tested as catalysts in the aldol condensation of furfural with cyclopentanone, which is an interesting reaction for the production of sustainable jet fuels, the highest catalytic activity is attained over the dendritic ZSM-5 materials due to their remarkable accessibility and balanced Brønsted/Lewis acidity.

Morbidity of laparoscopic surgery for complicated appendicitis: an international study

BACKGROUND

Although laparoscopic appendectomy has some advantages over open appendectomy, some reports do show more postoperative intraabdominal abscesses.

METHODS

A retrospective review of complicated appendicitis managed surgically by eight surgical groups from six countries was undertaken. Among 3,433 patients with appendicitis, 1,017 (29.5%) had complicated appendicitis, which included perforated or gangrenous appendicitis with or without localized or disseminated peritonitis. There were 74 preoperative abscesses (7.4%) and 5 small bowel obstructions.

RESULTS

One patient died. There were 29 postoperative intraabdominal abscesses (2.8%) and 112 mostly minor complications. Conversion to laparotomy was necessary for 28 patients (2.7%). The surgical time ranged from 32 to 132 min (mean, 62 min), and the hospital stay ranged from 1 to 18 days (mean, 3.5 days).

CONCLUSIONS

The morbidity rates, particularly for intraabdominal abscesses, were less for laparoscopic appendectomy in complicated appendicitis than those reported in the literature for open appendectomy, whereas operating times and hospital stays were similar.

Laparoscopic repair of traumatic diaphragmatic hernia

Posttraumatic diaphragmatic rupture or eventration is still a challenging problem. Herein five cases of patients with such a diaphragmatic lesion treated successfully by laparoscopy are reported with a discussion of the advantages of this mini-invasive surgical approach.

Technical modifications for laparoscopic appendetomy and other pelvic procedures using microinstruments

Reusable microinstruments are used in a modification of the three-port technique for laparoscopic appendectomy and other pelvic procedures; the method is described herein. Fifty-seven consecutive patients were operated upon using this technique. There was no mortality; there were two minor complications and no conversions to laparotomy. Pain medication needs were minimal in all patients, and the cosmetic results were excellent. The use of microinstruments for pelvic laparoscopic procedures is safe and cost-effective using the technical modifications described.

Laparoscopic diagnosis and treatment of an acute epiploic appendagitis with torsion and necrosis causing an acute abdomen

Acute epiploic appendagitis is not as rare as previously thought; but, since the presenting signs and symptoms are not specific, preoperative diagnosis has been rarely made. At the present time, a laparoscopic exploration of the peritoneal cavity will establish the correct diagnosis, and the treatment can be provided during the same procedure. Herein, a case of a 63-year-old female patient with acute abdominal syndrome caused by a necrotic epiploic appendix that was successfully diagnosed and treated laparoscopically is described. A review of the literature is made, as well.

[Critical vision in the treatment of invasive vesical cancer with ionizing radiation]

OBJECTIVE

To review the treatment of invasive bladder cancer with ionizing radiation.

METHODS

Patient selection criteria, prognostic factors, treatment of different tumor types with radiation using different strategies alone or in combination with chemotherapy are analyzed in the literature.

RESULTS/CONCLUSIONS

The role of radiotherapy in the treatment of invasive carcinoma of the bladder is crucial: 1) preoperative radiotherapy in combination with radical surgery achieves results comparable with those of cystectomy in terms of survival and a higher local control rate; 2) used in combination with cisplatin post-TUR, irradiation is highly effective for local control of the tumor and bladder preservation, with complete remission rates ranging from 60-70%, which are higher than those of radical cystectomy; 3) in this latter therapeutic modality the effect of radiotherapy is dose-related and is influenced by factors such as tumor size, presence or absence of urinary obstruction, presence of multiple lesions on the bladder wall and extravesical spread. Over the last few years, a number of therapeutic procedures have been developed, which can improve the previously mentioned results when used appropriately. Among these are hyperfractionation, accelerated irradiation and concomitant radio and chemotherapy. Studies to determine tumor radiosensitivity (Fs2/a) and the use of gene therapy could enhance the tumor control rate in the future, although a system for the selection on patients for conservative or multilating treatment based on clinical, clinicopathological and scientific criteria will have to be developed. Finally, the use of special techniques, particularly brachytherapy and intraoperative irradiation, in combination with external radiotherapy has achieved excellent results (high local control and survival rates) in certain situations, basically in single/small-sized tumours.

Laparoscopic repair of pleural laceration produced during truncal vagotomy: case report

A partial pneumothorax developed in a patient undergoing laparoscopic truncal vagotomy when a small pleural laceration was accidentally produced. Changes in oxygen saturation and PETCO2 were immediately detected by the anesthesiologist and measures were taken to maintain the patient's ventilatory stability. The pleural laceration was repaired laparoscopically, and the pneumothorax was corrected by ventilatory manipulation, avoiding the placement of a chest tube. The procedure was completed uneventfully. Literature about the causes of pneumothorax during laparoscopic procedures as well as preventive and therapy viewed.

Laparoscopic-assisted resection of a bleeding gastrointestinal stromal tumor

The authors report a case of a 29-year-old male patient with a severe lower gastrointestinal hemorrhage in whom a successful laparoscopic diagnosis and resection (assisted) of an ileal gastrointestinal stromal tumor (GIST) was performed. Laparoscopy can be very useful in the diagnosis and treatment of selected cases of lower gastrointestinal bleeding.

Stoppa-type laparoscopic repair of complex groin defects

With the laparoscopic approach, bilateral and complex groin defects can be corrected simultaneously by applying a preperitoneal mesh that covers the entire posterior wall of the groin, using a technique similar to the one described by Stoppa. We present our series of hernias repaired by the transabdominal preperitoneal laparoscopic approach with the Stoppa-type technique. The report consists of 78 cases of bilateral defects, of which 60% were indirect bilateral hernias, 23% direct bilateral, and 17% combined defects; 28.5% were recurrent hernias. Only minor complications were observed (hematomas and urinary retention) in some patients, but all resolved spontaneously. Three recurrences (0.7%) have been seen to this date. This method is recommended as the method of choice for complex groin defects.

Retrieval of specimens in laparoscopy using reclosable zipper-type plastic bags: a simple, cheap, and useful method

Surgical specimens must often be extracted during laparoscopic surgery. Although the technologic advances in this field are amazing, simple measures may sometimes work even better than very sophisticated instruments. This is true of the reclosable plastic bags with zipper-type closure that we use for retrieving surgical specimens from the abdominal cavity in order to protect it as well as the abdominal wall. The bags are cheap, offer no problems for sterilization, are easy to obtain, and are available in many sizes. They are very simple to handle, making it easy to slip in the specimen and then extract it from the abdominal cavity. We describe our experience with these bags and a technique for manipulating them.

Bowel obstruction in the postoperative period of laparoscopic inguinal hernia repair (TAPP): review of the literature

A case is presented of a male patient that presented with intestinal obstruction in the early postoperative period of a transabdominal preperitoneal inguinal repair (TAPP) that was diagnosed and repaired successfully using laparoscopy. Whenever a total extraperitoneal procedure (TEP) cannot be performed, the peritoneal closure of the TAPP should be done water-tight using interrupted stitches of absorbable monofilament sutures.

The efficacy of laparoscopic surgery in the diagnosis and treatment of peritonitis. Experience with 107 cases in Mexico City

BACKGROUND

Peritonitis continues to be an important cause of morbidity and mortality and often an etiologic diagnosis is unclear. To evaluate the efficacy and safety of laparoscopy the authors analyzed their 5-year experience with this modality of treatment.

METHODS

A review was made of 107 consecutive nonselected laparoscopic procedures performed between October 1990 and November 1995. The diagnosis was established by clinical, laboratory, and imaging findings and confirmed by laparoscopy and/or laparotomy.

RESULTS

An etiologic diagnosis was unclear in 35% of the cases and was established in all by laparoscopy; 94 patients (87.9%) were successfully treated by laparoscopy while 13 (12.1%) required conversion. Mortality was 4.6%; 14% had postoperative complications and 7.4% had reoperations.

CONCLUSIONS

Laparoscopic surgery is safe and very efficient in the diagnosis and treatment of patients with peritonitis. In most instances a definitive treatment can be carried out without conversion and has the additional and well-known advantages of minimally invasive surgery.

Use of subdiaphragmatic bupivacaine instillation to control postoperative pain after laparoscopic surgery

Although postoperative pain has been reduced significantly since the advent of laparoscopic surgery, many patients still complain of moderate abdominal and shoulder pain during the first 48 to 72 h after surgery. In this study, the effect of subdiaphragmatic instillation of bupivacaine after laparoscopic cholecystectomy was investigated. The evaluation of postoperative pain was done according to a numerical verbal scale and the dose of analgesia required. The results showed a considerable reduction of postoperative pain during the first 48 h after surgery in patients who received bupivacaine instillation. Although the literature shows certain controversy as to the effects of similar methods, our study concludes that instillation of a long-acting anesthetic, such as bupivacaine, into the subdiaphragmatic space after laparoscopic procedures is effective in postoperative pain reduction.

Laparoscopic treatment of perforated duodenal ulcer

We present a case of a perforated duodenal ulcer in an elderly malnourished, septic, diabetic patient with abnormal renal function. This patient was treated successfully with laparoscopic surgery. We suggest that similar cases can be treated by this method.

Experimental liver injury in the rhesus monkey. I. Effects of cirrhogenic diet and ethanol

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Cannulation of the thoracic duct and umbilical vein in patients with portal hypertension

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Vectorcardiographic studies in acquired valvular disease with reference to the diagnosis of left ventricular hypertrophy

A vectorcardiographic study using the Schmitt-Simonsen (SVEC-III) method was done in 92 patients with mitral and aortic acquired valvular disease in which left ventricular hypertrophy and the valvular lesions were proven by means of right and left heart catheterization, operation, or autopsy, or by all methods. Significant differences were found among groups with aortic insufficiency, aortic stenosis, and mitral insufficiency. The magnitude of the 0.01 and 0.02-sec and maximal spatial vectors and the voltages of the Q x , R x , as well as R z waves were greatest in the group with aortic insufficiency. The greatest voltages of the 0.03-sec and 0.04-sec vectors were found in patients with aortic stenosis. In this study the smaller voltages after the 0.03-sec vector were found in the group with mitral insufficiency, and these voltages were significantly increased when aortic insufficiency complicated the picture. Groups with aortic insufficiency and mitral insufficiency, or aortic stenosis or insufficiency and mitral stenosis showed abnormal inferior orientation of the middle and terminal forces, which were explained upon the basis of the concomitant right ventricular hypertrophy. The authors believe that with the aid of the corrected orthogonal system of Schmitt and Simonsen (SVEC-III) the clinician will be able not only to make a more accurate evaluation of left ventricular hypertrophy, but also in many instances will find considerable assistance in arriving at a specific clinical diagnosis.

Vectorcardiographic studies in acquired valvular disease with reference to the diagnosis of right ventricular hypertrophy

The orthogonal vectorcardiogram described by Schmitt and Simonson has been studied in 37 patients with "pure" mitral stenosis.

The diagnosis of right ventricular hypertrophy (RVH) could be established from changes in the magnitude, azimuth, and elevations of the initial, middle, and terminal forces, which could not be detected by the routine 12-lead electrocardiogram. This type of [see figure in the PDF file] recording has proved to be of great value in the diagnosis of right ventricular hypertrophy, particularly when the hypertrophy is of mild or moderate degree. Analysis of the instantaneous vectors has proved to be the single most important criterion in the electrocardiographic diagnosis of right ventricular hypertrophy.