Search

Evidence of prophylactic clipping is inconsistent except for proximal and large colonic lesions in the general population. Although warfarin and direct oral anticoagulants (DOACs) are significant risk factors of postpolypectomy bleeding (PPB), dedicated studies to examine the benefit of prophylactic clipping in these high-risk patients remain limited.We performed a propensity score-weighted retrospective cohort study from 2012 to 2020. Patients who received an oral anticoagulant and underwent colonoscopic polypectomy were included. Data were collected on baseline demographics, medications (anticoagulant, antiplatelet, and heparin bridging), and endoscopies (polyp number, location, size, morphology, histopathology, resection method and prophylactic clipping). Propensity-score models with inverse probability of treatment weighting were developed between prophylactic clipping and no clipping groups. Unbalanced variables were included in a doubly robust model with multivariate analysis. The primary outcome was clinically significant delayed PPB, defined as a composite endpoint of hemoglobin drop ≥2 g/dL, blood transfusion, or repeat colonoscopy for hemostasis within 30 days.Five hundred forty-seven patients with 1485 polyps were included. Prophylactic clipping was not associated with a reduced risk of PPB (odds ratio [OR], 1.19; 95% confidence interval [CI], .73-1.95; P = .497). The hot resection method was associated with a significantly higher risk of PPB (OR, 9.76; 95% CI, 3.94-32.60; P .001) compared with cold biopsy or snare polypectomy. In a subgroup analysis, prophylactic clipping was associated with a lower PPB risk in patients on DOACs (OR, .36; 95% CI, .16-.82; P = .015).Prophylactic clipping was not associated with an overall reduced risk of PPB in patients on oral anticoagulants. The use of cold snare polypectomy should be maximized in anticoagulated patients.

One type of frequently occurring construction accident is the failure of falsework systems during demolition and in new construction work. This paper describes a falsework monitoring system utilizing IoT to detect and report abnormalities prior to the occurrence of an accident. The contents presented include the research and design of special new sensor devices, communication means, temporary support structure and the adopted IoT means to improve safety.

Aim We investigated the role of paraaortic lymph node dissection (PALND) in patients with stage IIIC1 endometrial carcinoma after surgery followed by adjuvant radiotherapy (RT) alone or chemoradiotherapy (CTRT). Methods We performed a subgroup analysis in 151 patients treated with adjuvant pelvic RT. Paraaortic-recurrence free survival, disease-free survival (DFS) and overall survival (OS) were analyzed. Results In adjuvant RT alone, PALND was significantly related to reduced risk of paraaortic recurrence (0% vs. 17.1%) and distant metastasis (4.5% vs. 19.5%) compared with the no PALND group. PALND affected 5-year DFS (90.2% vs. 58.9%, p = 0.016) and OS (100% vs. 83.1%, p = 0.022). For the CTRT group, the paraaortic recurrence rate was 19.5% for the no PALND group and 12.8% for the PALND group (p = 0.682). Of patients who underwent PALND in the CTRT group, less extensive PALND was significantly related to increased paraaortic recurrence (≤10 vs. >10 dissected LNs, 17.1% vs. 0%). In the no PALND group (n = 82), 5-year paraaortic-recurrence free survival was 79.4% for the CTRT group and 76.2% for the RT alone group (p = 0.941). In multivariate analysis, PALND was significantly associated with reduced risk of disease-specific death (HR, 0.50; 95% CI, 0.26–0.96; p = 0.037). Conclusion PALND provided excellent paraaortic control and improved outcome in stage IIIC1 endometrial cancer with favorable tumor features treated with adjuvant RT alone. Less extensive PALND was associated with significantly increased paraaortic recurrence in patients with advanced tumor features treated with adjuvant CTRT. Combined CTRT did not affect disease control in the paraaortic region compared with RT alone.

Objectives To describe the percentage of pediatric outpatient pharmacy prescriptions with inappropriate prescribing identified by a pharmacist that resulted in a change to the prescription. Secondary objectives include describing types of inappropriate prescribing errors, prevalence of Institute of Safe Medication Practices high-alert medications, patient demographics, prescriber origin, and prescription origin. Methods This retrospective outpatient prescription record review was approved by an institutional review board and performed at an outpatient pharmacy located in an academic teaching hospital. The study reviewed pediatric outpatient prescriptions for a 6-month period. Prescriptions with prescribing errors were identified from pediatric prescriptions sent to the problem queue and documented with appropriate pharmacist notes. Results This study demonstrated the impact of a dose checking procedure and pharmacist interventions on pediatric prescriptions. Initial results show that 3% of all pediatric prescriptions required a pharmacist intervention. Of these prescriptions, 50% resulted in a change to the original prescription. Conclusion Weight-based dose checking in a pediatric outpatient pharmacy proactively prevents potential adverse events among the pediatric population. Despite this study's limitations, we believe that a pediatric dose checking procedure in community pharmacies will reduce adverse events. Further study is warranted in this field.

Informed by Coase's (1988) idea that state rules can enlarge a market, Rosa's (2006) idea of information as a private good usable as memes, and Yu's (1981) economics of patent pooling, Schuster's (2005) proposition that government can collect and distribute information as an active tool to influence actors, this paper advances the viewpoint that real estate development forms sign structures for adding information that enhances the values of a site under strategically selected property names. The ideal case of Hong Kong's planning and development by contract is used and compared to the practice in Mainland China to demonstrate these ideas with special reference to its open land registration and information systems, which sell important information memes and the names of properties that can be protected by trademark law.

Background Aberrant activation of Wnt/β-catenin signaling is commonly found in colorectal cancers (CRCs) and is the prime event involved in the rapid proliferation of tumor cells in patients with advanced CRC. However, the limited effects of current therapeutics are unsatisfying, which highlights the importance of novel interventions in CRC chemo-treatment. We designed a highly potent small-molecule inhibitor CWP232228, which antagonizes binding of β-catenin to T cell factor in the nucleus. Thus, the present study aimed to explore the possibility of a selective small molecule β-catenin inhibitor, CWP232228, as a potential therapeutic drug in the treatment of CRCs. Methods We observed that CWP232228 at a concentration of as low as 1.0 μm induced significant cytotoxic effectsand apoptosis in HCT116. Immunoblot analysis showed that CWP232228 treatment increased the release of cytochrome C, which led to the activation of apical (caspase-9) and effector caspases (caspase-7 and -3) resulting in the increased cleavage of PARP. Results In addition, we observed that CWP232228 caused cell cycle arrest via attenuating the expressions of cyclin D2, D3, and survivin. Thus, we validated decreased expressions of Wnt/β-catenin targeted cell cycle progression regulators, aurora kinase A, c-Myc, cyclin D1, and microphthalmia-associated transcription factor. Conclusions We confirmed that CWP232228 targets β-catenin via decreased promoter activities, nuclear expressions of β-catenin. Lastly, we found CWP232228 also inhibited growth of xenografted colon cancer cells in NOD-scid IL2Rgammanull mice. Collectively, results in the current study showed a possibility for CWP232228 as a potential therapeutic drug in CRCs. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

The derivation of a new conceptual model for predicting the peak penetration resistance of circular footings installed vertically into sand overlying soft clay is presented in this paper. Based on visualisation experiments and finite-element analyses, a failure mechanism of a frustum of sand being forced into the underlying clay, with the outer angle reflecting the dilation in the sand, is assumed. The analytical basis of the new conceptual model follows the approach for silo analysis, and takes into account the stress level and dilatant response of the sand. A comprehensive analysis of the performance of the new model, and other existing analytical methods, in retrospectively predicting the peak resistance of a database of 49 geotechnical centrifuge tests is provided. Significant improvements over existing punching shear and load spread models are shown, as a result of incorporating the strength properties of the sand in a consistent manner. The new model has application to the offshore mobile ‘jack-up' industry, where inaccurate predictions of peak capacity in layered soils continue to cause damaging punch-through failures.

Vascular-related toxicities have been reported among survivors of Hodgkin lymphoma (HL), but their genesis is not well understood.Fasting blood samples from 25 previously irradiated HL survivors were analyzed for biomarkers that can reveal underlying inflammation and/or endothelial cell activation: high-sensitivity C-reactive protein (hsCRP), triglycerides, total cholesterol, high-density lipoprotein (HDL), apolipoprotein ß, lipoprotein (a), fibrinogen, circulating endothelial cells (CECs), and vascular cell adhesion molecule-1 (VCAM-1) expression. Values were compared to subjects in the Coronary Artery Risk Development in Young Adults (CARDIA) study. CECs and VCAM-1 were compared to healthy controls.Survivors (76% male), median age 17.6 years (5-33) at diagnosis, 33.0 years (19-55) at follow-up, included stages IA (n = 6), IIA (n = 10), IIB (n = 2), IIIA (n = 4), and IVA (n = 3) patients. Twenty-four received at least chest radiation therapy (RT) (median dose 3,150 cGy; range: 175-4,650 cGy), one received neck only; 14 (56%) had a history of anthracycline exposure (median dose: 124 mg/m(2) range: 63-200 mg/m2). Compared to CARDIA subjects, mean hsCRP (3.0 mg/L ± 2.0 vs. 1.6 ± 1.9), total cholesterol (194.1 mg/dl ± 33.2 vs. 179.4 ± 32.9), lipoprotein (a) (34.2 mg/dl ± 17.5 vs. 13.8 ± 17.5), and fibrinogen (342.0 mg/dl ± 49.1 vs. 252.6 ± 48.4) were significantly elevated. CECs (2.3 cells/ml ± 1.5 vs. 0.34 ± 1.4) were significantly elevated compared to controls. No difference in VCAM-1 expression (51.1% ± 36.8 vs. 42.3 ± 35.6) was detected.HL survivors exposed to RT have evidence of vascular inflammation, dyslipidemia, and injury suggestive of early atherogenesis.

It was investigated that two plates of aluminum can be welded by hot extru-shear welding process with extru-shear welding dies, and that the welding strength and metal flow on the welding section were analyzed by computer simulation according to the welding variables such as inclined angle of cutter and overlapped length of plates and temperature of plates. It was known by computer simulation that welding strength on the welding section of plates could be influenced by the inclined angle of cutter and overlapped length of plates and temperature of plates. And it was known by experiments that two plates of aluminum can be welded on the end sections by hot extru-shear welding process using extru-shear welding dies, and that welding strength is the highest when inclined angle of dies is 70 o , and overlapped length is 1.2 mm, and temperature is 520 o , when aluminum 5052 two plates with 1.6 mm thickness are used as welding material. Key Words : Extru-Shear Welding(ESW), Extru-Rivet Welding(ERW), Pressure Welding, Friction Stir Welding, Welding Dies, Aluminum Plate

It was investigated that two rods of aluminum can be welded by hot extru-pressure welding method with stepped welding dies, and that the welding pressure and metal flow on the welding surface were analyzed by computer simulation according to the stepped shapes of welding dies. It was known by computer simulation that welding pressure on the welding section of rods welded using stepped welding dies could be higher than the welding pressure of aluminum rods without using stepped welding die. And it was known by experiments that two rods of aluminum can be welded on the end sections by hot extru-pressure welding method using stepped welding dies without relative rotational movement of contacted aluminum rods in the case of friction welding of rods.

A real-time wireless system using hybrid automatic repeat request to correct errors is analyzed. Packet errors are modeled by a two-state Markov chain, and batch packet arrivals are allowed. Packets are dropped at the sender if their delays exceed a time limit, possibly after a number of retransmissions. Using the delay-model approach, a closed-form expression of packet-loss probability (PLP) and an approximate formula of wireless effective bandwidth (WEB) satisfying the quality of service requirements have been derived. If Bose–Chaudhuri–Hocquengem codes are used, an expression estimating the number of correctable bits to minimize the PLP has also been obtained. Moreover, the WEB is found to be independent of the packet size, and the PLP decreases exponentially as the WEB increases.

Aim. This paper reports a study to explore the expectations, attainments and opinions of the participants, the objectives and experiences of nurse facilitators, and the changes in nurse–client relationship after a small-group hypertension health education programme. Background. Effective control of blood pressure among hypertensive patients is essential in the reduction of cerebrovascular-related morbidity and mortality. A ‘small-group hypertension education programme’ has been implemented in all general outpatient clinics in Hong Kong since 2000. In order to identify what aspects of the programme were beneficial and how it benefited clients, a process evaluation study was conducted. Methods. Following implementation of a small-group hypertension health education programme, two focus groups were run to collect data from eight nurse facilitators, and individual semi-structured interviews were conducted with 16 programme participants. The data were collected in 2001. Findings. The findings indicate that both clients and nurses gained a great deal from and enjoyed the process of this health education programme, and their relationships were improved after the programme. About half of the clients reported having adopted health-enhancing behaviour. The study also revealed discrepancies between the nurses and clients in their perceptions of the objectives of the programme. This indicates that there is a need to clarify the objectives with clients to minimize disappointments from unrealistic expectations. Conclusion. There is a need for the nurse facilitators to clarify the goal of the programme as an education group rather than as a support group. Also, needs assessment is suggested before group member recruitment in order to make the group more homogeneous.

Purpose – Anisotropic conductive adhesive film (ACF) is used for very fine pitch applications in the microelectronics industry, such as flip chip (FC) technology. During the bonding process, bumps on the chip and pads on the substrate are first aligned and then heat and pressure are applied so as to apply thermal energy to the ACF for curing and to cause permanent plastic deformation of the conductive particles. Consequently, a permanent electrical and mechanical contact is formed between the bumps and the pads. The purpose of this study is to investigate the effect of the size and location of any voids in the ACF during subsequent solder reflow processes necessary for SMT component attachment. The paper also investigates the use of a protective aluminium cover during such reflow cycles, which reduces the temperature inside the ACF, and therefore, the stresses inside the ACF, especially when voids exist.Design/methodology/approach – In this study, the ACF is a temperature dependent material having various...

White-rot fungi, namely Coriolus versicolor and Schizophyllum commune, were studied for the biodecolorization of textile dyeing effluent in shaker-flask experiments. The results showed that C. versicolor was able to achieve 68% color removal after 5 days of treatment while that of S. commune was 88% in 9 days. Both fungi achieved the above results in non-sterile condition with diammonium hydrogen phosphate as the nutrient supplement. On the other hand, the best COD removal of 80% was obtained with C. versicolor in 9 days in sterile effluent with yeast extract as nutrient supplement, while S. commune was able to remove 85% COD within 8 days in non-sterile textile effluent supplemented with diammonium hydrogen phosphate.

In this work, two Markov chains modeling packet delay have been developed to obtain closed-form solutions for packet loss probabilities and packet delay distributions in a real-time wireless communication environment. Packets with delay constraints are queued at the source and are transmitted one by one with possible retransmissions to correct errors. The first model models packet delay and correlated packet arrivals using a one-dimensional Markov chain. Usually, at least two dimensions are needed in queuing models. The second model is a two-dimensional Markov chain modeling packet delay, correlated channel errors, and correlated arrivals. Both correlated errors and arrivals are known to have significant impact on packet loss. Possible applications of the results are also discussed.

A novel Markov model is constructed to calculate the packet loss probability and the delay distribution of real-time wireless packets. These packets are transmitted through an erroneous channel modeled by a two-state Markov chain. If a packet transmission is not successful, the packet is retransmitted until a delay limit is exceeded. At that time, the packet is discarded and the transmission of the next packet begins. This packet-dropping process has a significant impact on packet loss probability but is seldom considered in other Markov models. Closed-form solutions are obtained, and simplified expressions assuming highly correlated errors and small error probability are derived. Under these conditions, it is found that the packet loss probability is significantly affected by the delay limit and the transition probability of the channel's remaining in the failure state. On the other hand, the probability is almost independent of the arrival rate provided the rate is not close to one.

Purpose: To examine the long-term outcome of Stage I, II, and III patients treated with curative radiotherapy for Hodgkin’s disease at the University of Minnesota Hospital, with particular focus on long-term treatment-related complications and the need for long-term surveillance after treatment. Methods and Materials: A total of 210 Stage I, II, and III patients (98 female, 112 male) treated at the University of Minnesota since 1970 were included in this study. All patients were laparotomy staged. Between 1970 and 1974, 35 high-risk patients (i.e., patients with large mediastinal mass, and/or hilar disease, and/or splenic involvement) and 40 low-risk patients were treated with standard field radiotherapy. From 1975 on, 67 high-risk patients received radical radiotherapy because of poor outcomes with standard radiotherapy, and 68 low-risk patients received standard radiotherapy. Salvage chemotherapy was given to 62 patients who recurred. Median follow-up for all patients was 15.6 years (range 0.35–26.5 years). Long-term complications after treatment were assessed using standardized incidence ratios (SIR) and mortality ratios (SMR), with particular focus on cardiac complications and secondary malignancies. Results: By study end, 70% of the patients are alive and 70% had never recurred. Complications included 33 second malignancies and 75 cardiovascular events. Patients treated for Hodgkin’s disease had about 7 times the risk of dying from cardiac problems (SMR = 7.2) and 10 times the risk of dying from a second malignancy (SMR = 10.3) compared to the general population. In terms of absolute risk, Hodgkin’s disease would cause seven additional deaths from secondary malignancies per year among 1000 patients and four additional deaths from cardiac problems. Conclusion: Hodgkin’s disease patients treated successfully with radiotherapy are at an increased risk for developing long-term treatment-related cardiac disease and/or second malignancies. Careful monitoring of these patients is essential to manage morbidity and minimize mortality from these complications. Suggestions for the establishment of worldwide surveillance programs for these patients are proposed.

The physical and chemical properties of polyaniline thin films produced by vapor deposition of aniline tetramers on a Cu(110) substrate have been investigated using high-resolution electron energy loss spectroscopy (HREELS). HREELS spectra showed that aniline tetramers are stable on the Cu(110) surface and do not react to form longer chains. Tetramer films doped with HCl exhibited HREEL spectra with features characteristic of a semiconductor. The physical properties of the tetramer films have also been compared to those of films grown by exposing Cu(110) to aniline oligomers produced via pyrolysis of bulk emeraldine. Those films exhibit thickness-dependent changes related to reactivity of the vapor with the surface and metallic spectral features upon doping with HCl.

This paper investigates the machinability of Cu-Be alloys by ultraprecision grinding and facing. The material temper, tool geometry, and machining parameters are varied to assess their effects on surface finish. The study shows that microgrinding of Cu-Be with a diamond wheel generates a rougher surface finish as compared to that produced by microfacing with a single-point diamond tool. Similar chip formation mechanisms are observed when the depths of cut vary from few millimeters to submicron levels. A mathematical model is derived to compare the theoretical and experimental surface finish. Good agreement between predicted and measured data is obtained, providing grain boundaries are visible on a machined surface when being observed under a microscope. Feedrate and tool radius are the most influential parameters on surface finish. Flatness of 20 nm on the 9.5 mm diameter rod and roughness of 2 nm Ra and 8 nm Rt are achieved. Although the material’s micromachinability is the same for both the aged and unaged alloys, size and distribution of beryllides must be controlled for better tool life and surface finish.

As a part of our fundamental studies on the acid function of catalysts for hydrocracking, alumina-pillared montmorillonite catalysts were prepared and characterized by means of temperature-programmed desorption with NH 3 from sulfided catalysts (TPD-S) and temperature-programmed reduction of sulfided catalysts (TPR-S). The TPD-S and TPR-S characteristics of catalysts thus obtained have been compared with the activities of cumene cracking in a pulse-type micro reactor. Commercial hydrocracking catalysts were also characterized with similar methods and the performance of cumene cracking was tested. TPD, TPR profiles and cumene cracking activity changed after sulfiding of alumina-pillared montmorillonite. Both the chemical property changes by the heat treatment and the sulfur species adsorbed on the surface allow us to alter its acid property and cumene cracking activity as well.

Carcinoma in situ of the glottic larynx is a rare malignancy, comprising only 1% to 2% of laryngeal biopsy. The management of these lesions remains controversial. In this article, the authors present results and analysis of the management of 20 patients having these lesions treated by radiotherapy. A total of 20 patients who had carcinoma in situ of the glottis were treated with curative intent with radiotherapy at the Veterans Administration Medical Center, Minneapolis, Minnesota, U.S.A. from November 1972 through March 1993. Before radiotherapy, eight patients had only biopsies of the glottic larynx, five had one stripping procedure, and seven patients had two or three stripping procedures. Of the 20 patients, 19 are available for retrospective analysis, with a minimum follow-up of 4 years and a median follow-up of 7.3 years. Treatment was given to all patients by megavoltage units (cobalt 60, 2; 4-mV linear accelerator, 18). Patients were treated using bilateral opposed wedged 6-cm x 6-cm fields, with a dose of 1.75 Gy per fraction to a total median dose of 68.4 Gy in 40 fractions over 56 elapsed treatment days. The Kaplan-Meier method was used for survival analysis. The 4-year disease-free survival was 95% after irradiation. The actuarial disease-free survival for 5 and 10 years was 95%. Surgical salvage failed in one patient who had a laryngectomy for recurrent invasive squamous cell carcinoma at 34 months after radiotherapy. Two patients developed severe shortness of breath because of laryngeal edema, which required tracheostomy. Sixteen patients reported subjective significant improvement of their voice quality, and four reported no change. Radiotherapy is an excellent choice for patients who have recurrent carcinoma in situ after undergoing stripping procedures or for those patients who live too far from a medical facility to allow close follow-up and repetitive surgical procedures. These results are comparable to those of other investigators who used radiotherapy with higher dose per fraction.

CoMo-Al2O3 catalyst was characterized with a combination technique of temperature-programmed sulfiding (TPS) and electron spin resonance (ESR). The behavior of the MoO3 loaded over the surface of Al2O3 obtained from TPS has been compared with that of Mo5+ observed with ESR at isothermal and elevated temperatures. The Mo6+ in the MoO3 supported is easily reduced with H2S+H2 under very mild conditions and transformed into Mo5+ as an intermediate. This Mo5+ peak drastically decreased around 200°C with H2S desorption, and H2 consumption appeared simultaneously in the TPS profile. These results suggest that the Mo5+ species observed with ESR associates with sulfur from H2S.

To identify factors associated with the prevalence of radiation proctitis in patients with prostate cancer treated with external radiation therapy and to determine if a dose-response relationship exists.The study included 101 prostate cancer patients treated at the University of Minnesota Hospital and Clinics between 1970 and 1987. Radiation therapy at a daily dose of 175-200 cGy was given for 5 consecutive days per week for 7 weeks with a 10-24-MV linear accelerator. Mean dose to the prostate was 6,795 cGy (range, 5,579-7,417 cGy). Simulation radiographs obtained with rectal barium were analyzed in 51 patients. Doses were calculated at specific points in the boost field.Radiation proctitis developed in 19 patients. No pretreatment or treatment factors were associated with a higher prevalence of proctitis. Statistically significant correlation (P.042) was found between the development of proctitis and dose to the posterior rectum. At chi 2 analysis, proctitis was statistically significantly (P.005) associated with posterior rectal doses of5,000 cGy.A high posterior rectal dose (5,000 cGy) is associated with increased prevalence of proctitis after radiation therapy.

We have studied the effect of frequency detuning on phase locking in a two-element laser array. The observed modal behavior near the boundary of the locked and unlocked states shows that a two-element laser array can not be characterized simply as a two-mode system. The implication of the new understanding on previous theoretical predictions of laser dynamics is discussed.

Research on the application of fuzzy set theory to the design of control systems has led to interest in decomposition of multivariable fuzzy systems. Decomposition of multivariable control rules is preferable since it alleviates the complexity of the problem, but the inference error is inevitable because of its approximate nature. In this paper we show that a large inference error is generated when the Gupta's decomposition method (1986) is applied to Exclusive-nor (ENOR) gate model which is used as a counter example. We define an index of applicability which can classify whether the decomposition method can be applied to a multivariable fuzzy system or not. >

In a “gain-guided” self- Q -switched laser with a large cross section, the time required for the development of a steady-state modal profile is longer than the pulse duration, resulting in transient profiles that considerably deviate from the steady-state profile prescribed by the eigen modes of the waveguide.

The formation of scale deposits is a serious problem in the operation of oil fields, desalination plants and geothermal wells. Oil field scales are formed mainly from the sparingly soluble sulfates and carbonates of calcium, strontium and barium. All the available sale prediction models are based on thermodynamics and, hence, can predict only the potential to form scale. To understand and predict actual scale formation, it is necessary to study and incorporate into scale prediction models, the kinetics and mechanism of precipitation from solution over wide ranges of temperature, pressure, ionic strength and supersaturation. The kinetic data available in the literature cover a reasonably wide range of supersaturation, but are in a narrow range of temperature around 298 K. There are hardly any discussions on the effects of ionic strength and pressure on spontaneous precipitation. In this work, the precipitation of strontium sulfate from supersaturated solutions was studied by monitoring the changes in strontium ion concentration during spontaneous precipitation. This work presents the experimental results on the effects of temperature and ionic strength on the rate constant. Kinetic rate expressions, which may be used in development of models for predicting scale formation, are developed.

Fracture of rocks containing a multitude of pre-existing cracks is considered from both theoretical and experimental points of view, paying attention mainly to the underlying mechanisms. The competition between a number of mechanisms in producing tear or shear type fractures is discussed in relation to the properties of the rock and the system of pre-existing cracks on the one hand and the type of loading on the other hand. First, 2-D theoretical models and experimental results aimed at the explanation and description of brittle fracture under compression are considered. Their insufficiency and the necessity to address the 3-D peculiarities of crack growth in rock are shown on the basis of new experimental results on 3-D crack propagation in transparent rock-like brittle materials under uniaxial compression. The results show that in contrast to the 2-D case, a single 3-D crack cannot propagate any appreciable distance and the loading results in dynamic, burst-like failure of the sample. Possible mechanisms of the routinely observed extensive fracture propagation in rock samples (splitting), as well as the possibility of shear (oblique) fracture in uniaxial compression, are discussed in connection with these experiments.

The kinetics of spontaneous precipitation of strontium sulfate in a batch reactor was investigated at various temperatures, pressures, and ionic strengths. Precipitation rate constants were determined at temperatures of 303 to 398 K, pressures from saturation to 13.8 MPa, and initial ionic strengths of 0.02 to 4.5 molal. The precipitation obeyed a second-order rate equation at moderate and small supersaturations and appeared to obey a first-order rate equation when the supersaturation was very low. The rate constant was found to be nearly independent of pressure and a strong function of temperature with an apparent activation energy of 59 kJ/mol. The rate constant decreased rapidly with an increase in ionic strength in the range of low ionic strengths, and decreased very slowly at ionic strengths greater than 2 molal.

Epilepsy is a chronic disorder affecting approximately 1% of the population of the world. Approximately one third of patients with epilepsy remain refractory to medical therapy. For these patients, surgery is a curative option. In order for surgery to be considered, precise localization of the structural abnormality is needed. When MR imaging findings are normal, more sensitive techniques such as positron-emission tomography (PET) can help find the abnormality. Combining MR imaging and PET information increases the sensitivity of the presurgical evaluation. In this review, we discuss the clinical applications of coregistration of [(18)F] fluorodeoxyglucose (FDG)-PET with MR imaging for medically refractory epilepsy. Because FDG-PET/MR imaging coregistration has been a routine component of the presurgical evaluation for patients with epilepsy at our institution since 2004, we also included cases from our data base that exemplify the utility of this technology to obtain better postsurgical outcomes.