Enhanced vibration performance of ultrasonic block horns

Block horns are tuned components designed to vibrate in a longitudinal mode at a low ultrasonic frequency. Reliable performance of such horns is normally associated with the amplitude of vibration, uniformity of vibration amplitude at the working surface and the avoidance of modal participation by non-tuned modes at the operating frequency. In order to maximise vibration amplitude uniformity, standard slotting configurations are included in the horn design. However, defining a slotted block geometry which guarantees sufficient tuned frequency isolation from nearby modes as well as high amplitude and amplitude uniformity, is not straightforward. This paper discusses horn configurations which satisfy these criteria and investigates the design requirements of block horns which operate as intermediate components in ultrasonic systems, where the block horn dominates the vibration behaviour of the system. The importance of mode shape characterisation is discussed and modes are classified using experimental data from 3D laser Doppler vibrometer measurements and finite element analysis. In particular, the role of additional fine slots and castellations are studied with reference to two distinct ultrasonic applications involving a similar block horn.

Influence of ultrasonics on upsetting of a model paste

This paper describes a preliminary study of the influence of ultrasonics on the boundary conditions associated with the equipment walls in a soft solid forming operation using Plasticine as a material model. A detailed finite element analysis is described involving the upsetting of a cylindrical specimen between two parallel rigid dies with kinematics and ultrasonic oscillatory loading conditions. A series of squeeze flow experiments has been conducted to validate the finite element models. The oscillation parameters were measured using a 3D laser Doppler vibrometer to complement the measurement of reaction forces.

Q2 Dependence of quadrupole strength in the gamma*p --> Delta(+)(1232) --> p pi(0) transition

Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q2 dependence of the magnetic (M1+), electric (E1+), and scalar (S1+) multipoles in the gamma*p-->Delta(+)-->p pi(0) transition. We report new experimental values for the ratios E(1+)/M(1+) and S(1+)/M(1+) over the range Q2 = 0.4-1.8 GeV2, extracted from precision p(e,e(')p)pi(0) data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.

Outcome after septic complications in J pouch procedures

BACKGROUND

Despite the wide range of surgical approaches for pouch salvage, septic complications are among the main causes of pouch failure.

METHODS

This study analysed the mode and outcome of various therapeutic approaches for pouch salvage and the impact of time of diagnosis, localization and form of septic complications on the risk of pouch failure in 131 patients with septic complications of a total of 706 patients undergoing a J pouch procedure.

RESULTS

Septic complications consisted of 76.3 per cent fistulas, 15.3 per cent anastomotic breakdowns and 8.4 per cent pelvic abscesses. A total of 107 patients (81.7 per cent) with septic complications required a mean of 2.2 surgical procedures. The frequency of permanent defunctioning and excision of the pouch in the 131 patients with septic complications was 23.7 and 6.1 per cent respectively. The estimated cumulative 3-, 5- and 10-year rate of pouch failure in patients with septic complications was 19.6, 31.1 and 39.2 per cent respectively. The risk of pouch failure was significantly affected by the site of origin of septic complications (P = 0.02). The 5-year pouch failure rate increased in a subgroup of patients with septic complications at the pouch-anal anastomosis when the anal sphincter was involved (50.1 versus 29.2 per cent; P = 0.18).

CONCLUSION

Pouch failure as a result of septic complications may occur several years after ileal pouch-anal anastomosis. For prevention of pouch failure, surgery for septic complications is required in a high percentage of patients and repeated attempts are justified. Follow-up studies are required for further analysis of pouch failure.

First measurement of the double spin asymmetry in (-->)e(-->)p-->e(prime)pi(+)n in the resonance region

The double spin asymmetry in the (-->)e(-->)p --> e(prime)pi(+)n reaction has been measured for the first time in the resonance region for four-momentum transfer Q2 = 0.35-1.5 GeV(2). Data were taken at Jefferson Lab with the CLAS detector using a 2.6 GeV polarized electron beam incident on a polarized solid NH3 target. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity-1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistent with a faster rise with Q(2) of the helicity asymmetry A1 for the F(15)(1680) resonance than expected from the analysis of the unpolarized data.

The genome sequence of Schizosaccharomyces pombe

We have sequenced and annotated the genome of fission yeast (Schizosaccharomyces pombe), which contains the smallest number of protein-coding genes yet recorded for a eukaryote: 4,824. The centromeres are between 35 and 110 kilobases (kb) and contain related repeats including a highly conserved 1.8-kb element. Regions upstream of genes are longer than in budding yeast (Saccharomyces cerevisiae), possibly reflecting more-extended control regions. Some 43% of the genes contain introns, of which there are 4,730. Fifty genes have significant similarity with human disease genes; half of these are cancer related. We identify highly conserved genes important for eukaryotic cell organization including those required for the cytoskeleton, compartmentation, cell-cycle control, proteolysis, protein phosphorylation and RNA splicing. These genes may have originated with the appearance of eukaryotic life. Few similarly conserved genes that are important for multicellular organization were identified, suggesting that the transition from prokaryotes to eukaryotes required more new genes than did the transition from unicellular to multicellular organization.

Outcome after septic complications in J pouch procedures

BACKGROUND

Despite the wide range of surgical approaches for pouch salvage, septic complications are among the main causes of pouch failure.

METHODS

This study analysed the mode and outcome of various therapeutic approaches for pouch salvage and the impact of time of diagnosis, localization and form of septic complications on the risk of pouch failure in 131 patients with septic complications of a total of 706 patients undergoing a J pouch procedure.

RESULTS

Septic complications consisted of 76.3 per cent fistulas, 15.3 per cent anastomotic breakdowns and 8.4 per cent pelvic abscesses. A total of 107 patients (81.7 per cent) with septic complications required a mean of 2.2 surgical procedures. The frequency of permanent defunctioning and excision of the pouch in the 131 patients with septic complications was 23.7 and 6.1 per cent respectively. The estimated cumulative 3-, 5- and 10-year rate of pouch failure in patients with septic complications was 19.6, 31.1 and 39.2 per cent respectively. The risk of pouch failure was significantly affected by the site of origin of septic complications (P = 0.02). The 5-year pouch failure rate increased in a subgroup of patients with septic complications at the pouch-anal anastomosis when the anal sphincter was involved (50.1 versus 29.2 per cent; P = 0.18).

CONCLUSION

Pouch failure as a result of septic complications may occur several years after ileal pouch-anal anastomosis. For prevention of pouch failure, surgery for septic complications is required in a high percentage of patients and repeated attempts are justified. Follow-up studies are required for further analysis of pouch failure.

Thapsigargin-induced calcium entry and apoptotic death of neutrophils are blocked by activation of protein kinase C

Intracellular free calcium ([Ca(2+)](i)) concentration, free oxygen radical (FOR) production, DNA breakdown, and plasma membrane phosphorylation were studied in human neutrophils activated with thapsigargin and phorbol myrisate acetate (PMA). Thapsigargin produced a rapid and sustained rise of [Ca(2+)](i), activated the endonuclease, and caused the breakdown of the neutrophil's DNA with a half-time close to 6 h. The protein kinase C activator PMA failed to inhibit the initial rise of [Ca(2+)](i), but inhibited the second phase of thapsigargin-induced calcium transient and completely blocked the activation of the endonuclease induced by thapsigargin. Thapsigargin induced a minor and delayed production of FOR, whereas PMA caused an abrupt and sustained FOR production that was enhanced by thapsigargin. Two plasma membrane proteins close to 50 and 64 kD were phosphorylated in PMA-activated neutrophils. These results suggest that the nonphosphorylated form of the membrane protein permits basal and thapsigargin-induced calcium entry. Phosphorylation by PMA of plasma membrane protein inhibits calcium uptake in both resting and thapsigargin-activated neutrophils and contributes to the block of the activation of the apoptotic endonuclease.

Chronic lymphocytic leukemia

This update of early stage B-cell chronic lymphocytic leukemia (B-CLL) embraces current information on the diagnosis, biology, and intervention required to more fully develop algorithms for management of this disease. Emphasis on early stage is based on the rapid advancement in our understanding of the disease parameters and our increasing ability to predict for a given early stage patient whether there is a need for more aggressive management. In Section I, Dr. Terry Hamblin addresses the nature of the disease, accurate diagnostic procedures, evidence for an early "preclinical" phase, the use of newer prognostic features to distinguish who will be likely to progress or not, and whether it is best to watch or treat early stage disease. In Section II, Dr. Neil Kay and colleagues address the biologic aspects of the disease and how they may relate to disease progression. Review of the newer insights into gene expression, recurring genetic defects, role of cytokines/autocrine pathways, and the interaction of the CLL B cell with the microenvironment are emphasized. The relationship of these events to both trigger disease progression and as opportunities for future therapeutic intervention even in early stage disease is also considered. In Section III, Dr. John Byrd and colleagues review the historical and now current approaches to management of the previously untreated progressive B-CLL patient. They discuss what decision tree could be used in the initial decision to treat a given patient. The use of single agents versus newer combination approaches such as chemoimmunotherapy are discussed here. In addition, the place of marrow transplant and some of the newer antibodies available for treatment of B-CLL are considered. Finally, a challenge to utilize our growing knowledge of the biology of B-CLL in the early stage B-CLL is proffered.

Reducing environmental emissions in tanneries

Tanning, in particular chrome leather production, is still characterised by an inefficient use of raw material and the production of highly polluted wastewater and solid wastes. A part of the emissions can be prevented by introducing clean tanning technologies, the remaining emissions can be treated. Clean production technologies and waste (water) treatment technologies should have a designed complimentarity. Anaerobic wastewater treatment with recovery of sulfides, sulfur and energy (biogas) is a cornerstone in such integral clean chrome leather technology.

["High pouch output" syndrome. Role of mineralocorticoid diagnosis after restorative proctocolectomy]

The two-phase restorative proctocolectomy is the treatment of choice for surgical therapy of the familial adenomatous polyposis (FAP) and also for the ulcerative colitis (UC). Besides the well-known complications the entire removal of the colorectum leads to an impairment of fluid and electrolyte resorption.

PATIENTS AND METHODS

Over a time period of two years we observed 320 proctocolectomized patients with ileal pouch-anal anastomosis (IPAA). All patients with high pouch output but without organic malfunction were identified. The organic reasons were excluded with the help of pouchoscopy, radiography or MR imaging. We evaluated routine parameters, the kidney function, the electrolyte changes, the acid-base balance and the urine pH, as well as the hormonal changes of the suprarenal glands. We identified seven patients with 'high pouch output' out of 320 patients observed. The control group consisted of 14 proctocolectomized patients without hints of complications in the endoscopic, radiographic and routine laboratory diagnostics.

RESULTS

Neither group showed any significant differences in the analysis of the routine parameters. A significant drop of the urine sodium concentration of 40.5 +/- 18.7 mmol/l (control group 98 +/- 43.4 mmol/l) was observed in the group with 'high pouch output'. In this group the plasma aldosterone values were strongly increased with an average of 42.6 +/- 28.9 ng/dl (control group 13.2 +/- 6.8 ng/dl) as well as the plasma 18-hydroxycorticosterone with an average of 153.7 +/- 121.1 ng/dl (control group 153.7 +/- 121.1 ng/dl). Neither group of patients showed increased activity of free corticosterone and free cortisol. Only free 11-desoxycorticosterone was elevated in the group with 'high pouch output'.

CONCLUSION

Our results prove that the mineralocorticoid adrenal activity plays a central role in order to preserve the volume and electrolyte homeostasis. The low frequency of 'high-pouch-output'-complications in realms of the restorative proctocolectomy proves the excellent compensation of the removal of the colon mucosa. Plasma aldosterone seems to be a diagnostic marker encapsulating the reabsorption problems of intestinal salt and volume losses after proctocolectomy.

Antibody therapy of acute and chronic leukemias

The development of antibody-based therapies for the treatment of both acute and chronic leukemias have undoubtedly been one of the most important advances in the treatment of leukemia. The importance of these novel agents lies not only in their unique mechanisms of action, but also their improved side effect profile which allows patients of advanced age or with significant co-morbid medical conditions to receive potentially beneficial therapies. Advances in therapeutic applications of monoclonal antibodies have come from a greater understanding of the biological characteristics of the antibody, as well as the target antigen, both of which impact the potential efficacy of a particular antibody. In the following review we will discuss the clinical development and potential roles of monoclonal antibodies in the treatment of both acute and chronic leukemias.

One- or two-stage procedure for restorative proctocolectomy: rationale for a surgical strategy in ulcerative colitis

OBJECTIVE

To analyze the results of different strategies for restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) in ulcerative colitis.

SUMMARY BACKGROUND DATA

No commonly accepted criteria exist for choosing between the one-stage or the two-stage procedure (with or without temporary diverting ileostomy) for IPAA. The authors analyzed the outcome of patients principally suitable for either of the two alternative surgical strategies.

METHODS

A matched-pair control study was performed, comparing surgical details and the early and late outcome of the one-stage (study group, n = 57) versus the two-stage procedure (control group, n = 114), for IPAA.

RESULTS

No differences were found between the study group and the control group regarding the matching criteria gender, median age at IPAA, systemic corticoid medication, or activity of colitis. Comparing the patients who underwent a one-stage procedure with those who underwent a two-stage procedure, the proportion of patients without complications was significantly higher (P =.0042) and the frequency of late complications was significantly lower (P =.0022) in patients who underwent the one-stage procedure. The percentage of patients with anastomotic strictures was significantly higher in the control group than in the study group (P =.0022). No significant difference was found between the two groups regarding early complications, pouch-related septic complications, pouchitis, median duration of surgery for IPAA, median blood loss, need for transfusion, or median hospital stay.

CONCLUSIONS

In patients with ulcerative colitis in whom there is a choice between a one-stage procedure or a two-stage procedure with a defunctioning ileostomy, the one-stage procedure is clearly superior. This finding is of great clinical relevance both for the subjective interests of the patient and from an economic point of view.

Essential and perceptual attributes of words in reflective and on-line processing

Access to essential and perceptual attributes of word meanings was investigated in a series of tasks. First, perceptual attributes of a number of natural kind concepts were determined by asking participants to generate the most salient features of those concepts; they were asked to assess the importance of both thosefeatures and features that fit criteria for essential attributes. Attributes fitting the criteria for essential attributes were found to be judged more important than perceptual attributes in identifying an object and to have more connections to other attributes of the concept. Semantic priming for both types offeatures was then investigated. Prime-target pairs consisting of the natural kind concept term and the perceptual or essential attribute were presented for lexical decision (Experiments 1a and 1b) or naming (Experiments 2a and 2b). Interstimulus intervals were either 0 or 200 ms. Both types of features were primed at a 200 ms interstimulus interval but only in the lexical decision task.

Resolution of oral ulcerations after decreasing the dosage of tacrolimus in a liver transplantation recipient

Oral ulcers have may possible causes, including immunosuppression and drug therapy. Severe cases of oral ulceration merit special consideration because the ulcers may become large enough to alter the quality of life of the patient. The present case involves a male patient who in 1994 received an orthotopic liver transplantation because of alcoholic cirrhosis. The initial immunosuppressive regimen was induced with tacrolimus (4 mg/d) and prednisone (20 mg/d). Ten months after orthotopic liver transplantation, the patient complained of multiple recurrent oral ulcers, dysphagia, and severe oral pain, which did not respond to any of the treatments over a 3-year period. Approximately 3(1/4) years after these unresponsive ulcers appeared, the reduction of the oral dosage of tacrolimus resulted in the total remission of the ulcers. A retrospective analysis demonstrated that appearance of the ulcers coincided with a dose of 9 mg/d of tacrolimus (whole blood levels of 12 ng/mL); the ulcers did not disappear until the dose was reduced to 4 mg/d (whole blood level of 6.6 ng/mL).

Photoproduction of the rho(0) meson on the proton at large momentum transfer

The differential cross section, d sigma/dt, for rho(0) meson photoproduction on the proton above the resonance region was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The rho(0) channel was extracted from the measured two charged-pion cross sections by fitting the pi(+)pi(-) and p pi(+) invariant masses. The low momentum transfer region shows the typical diffractive pattern expected from Reggeon exchange. The flatter behavior at large -t cannot be explained solely in terms of QCD-inspired two-gluon exchange models. The data indicate that other processes, like quark interchange, are important to fully describe rho photoproduction.

Breath sounds, asthma, and the mobile phone

The sounds generated by breathing in asthma are widely accepted as an indicator of disease activity. We have investigated the use of a mobile phone and electronic signal transfer by e-mail and voice mail to study tracheal breath sounds in individuals with normal lung function and patients with chronic or exercise-induced asthma. Spectrograms from patients with active asthma and impaired lung function were significantly different from people without asthma (p<0.0001). Our results suggest that mobile phone recordings clearly discriminate tracheal breath sounds in asthma and could be a non-invasive method of monitoring airway diseases.

D-penicillamine in systemic sclerosis? Yes!

The use of D-penicillamine in systemic sclerosis (SSc) has been controversial. We have reviewed the major published studies on this drug in SSc with diffuse cutaneous (dc) involvement and summarized our own recent experience in dcSSc patients treated with and without D-penicillamine. We conclude that D-penicillamine favourably alters the natural history of skin involvement in dcSSc, even when used in low dose. Furthermore, recurrence of diffuse skin change after discontinuation of D-penicillamine and improvement in skin thickening after reinitiation of the drug support its effectiveness. We believe that the rheumatologic community should use D-penicillamine in patients with early dcSSc.

Segmental mandibular reconstruction by microincremental automatic distraction osteogenesis: an animal study

We investigated the reconstruction of a surgically created critical size mandibular defect in sheep using a newly developed automatic distraction device. The device has an implantable component, which is fixed to the mandible to allow the transfer of the transport disc across the created defect, and an external component which is mounted on the activation pump and secured away from the site of bone distraction. Compression of the bellows in the external component causes fluid to be forced through the connecting tube into the distraction component. Distraction at a rate of 1 mm over 24 h was achieved in six sheep. New bone generated at the site of the created defects both anterior (compression side) and posterior (tension side) to the transport disc and had similar radiodensity to the adjacent mandibular bone eight weeks after the completion of distraction.