Determination Of Optimal Time Research Articles

Intraperitoneal chemotherapy for colorectal cancer peritoneal metastasis

Peritoneal metastasis is one of the common site of colorectal cancer metastasis and associated with a poor prognosis. The core strategy for colorectal cancer peritoneal metastasis primarily revolves around a comprehensive treatment approach with cytoreductive surgery and systemic chemotherapy as the mainstay, supplemented by intraperitoneal chemotherapy. As an important supplement to treatment, intraperitoneal chemotherapy has broad application prospects. The main modalities are hyperthermic intraperitoneal chemotherapy (HIPEC), neoadjuvant intraperitoneal and systemic chemotherapy (NIPS), early postoperative intraperitoneal chemotherapy (EPIC), sequential postoperative intraperitoneal chemotherapy (SPIC), normothermic intraperitoneal chemotherapy (NIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC). To promote the standardized application of intraperitoneal chemotherapy, further research on the mechanisms underlying peritoneal metastasis of colorectal cancer, selection of effective intraperitoneal chemotherapy agents, determination of optimal timing and administration protocols, exploration of the feasibility of sequential intraperitoneal chemotherapy and conduction of valuable basic and clinical research are currently needed. This paper will review the development and origins of intraperitoneal chemotherapy, treatment modalities, as well as the current application status and prospects of various treatment approaches in the context of peritoneal metastasis of colorectal cancer.

Prophylactic Intra-abdominal Drains in Major Elective Surgeries: A Comprehensive Review.

This comprehensive review explores the use of prophylactic intra-abdominal drains in major elective surgeries, offering a retrospective analysis of their historical evolution, current evidence, and implications for clinical practice. The definition and rationale for drain placement are elucidated, emphasizing their role in preventing postoperative complications. The review synthesizes conflicting evidence, acknowledging the efficacy of drains in specific surgical contexts while addressing concerns and criticisms regarding associated complications. The implications for clinical practice underscore the importance of a nuanced and individualized approach, incorporating shared decision-making between healthcare providers and patients. Looking ahead, areas for future research are identified, including the refinement of patient selection criteria, determination of optimal timing and duration of drain use, and exploration of innovative alternatives. This review contributes to the ongoing discourse as surgical practices evolve, providing insights that may shape evidence-based recommendations and refine best practices in major elective surgeries.

Bayesian Information-Theoretic Calibration of Radiotherapy Sensitivity Parameters for Informing Effective Scanning Protocols in Cancer

With new advancements in technology, it is now possible to collect data for a variety of different metrics describing tumor growth, including tumor volume, composition, and vascularity, among others. For any proposed model of tumor growth and treatment, we observe large variability among individual patients’ parameter values, particularly those relating to treatment response; thus, exploiting the use of these various metrics for model calibration can be helpful to infer such patient-specific parameters both accurately and early, so that treatment protocols can be adjusted mid-course for maximum efficacy. However, taking measurements can be costly and invasive, limiting clinicians to a sparse collection schedule. As such, the determination of optimal times and metrics for which to collect data in order to best inform proper treatment protocols could be of great assistance to clinicians. In this investigation, we employ a Bayesian information-theoretic calibration protocol for experimental design in order to identify the optimal times at which to collect data for informing treatment parameters. Within this procedure, data collection times are chosen sequentially to maximize the reduction in parameter uncertainty with each added measurement, ensuring that a budget of n high-fidelity experimental measurements results in maximum information gain about the low-fidelity model parameter values. In addition to investigating the optimal temporal pattern for data collection, we also develop a framework for deciding which metrics should be utilized at each data collection point. We illustrate this framework with a variety of toy examples, each utilizing a radiotherapy treatment regimen. For each scenario, we analyze the dependence of the predictive power of the low-fidelity model upon the measurement budget.

P1371Catheter-induced premature ventricular complexes (pvc) may aid in the determination of optimal timing for clinical pvc ablation

Abstract Background There is significant interpatient variability regarding the timing of the earliest local activation relative to surface QRS during premature ventricular complex (PVC) ablation. The aim of the present study is to evaluate whether catheter-induced premature ventricular complexes (PVCs) produced at the presumptive ablation site may aid in the identification of the optimal timing of the earliest local activation for the successful ablation of clinical PVCs. Methods Sixty-three consecutive patients (35 males, age: 53.5 ± 14.4 years) without any exclusion criteria who had undergone PVC ablation between 01/07/2018 and 01/07/2019 constituted our study population. Catheter-induced PVCs were generated at the site with presumptive PVC origin according to the ECG criteria during the procedure of PVC ablation. Five PVCs were induced by mechanical stimulation in separate points, and the time interval between the beginning of EGM at catheter tracing and the beginning of the QRS complex of each catheter-induced PVC was noted. The mode of five time intervals (Cath EGM-ECG) was used in the analysis. The time interval between the beginning of local EGM of clinical PVCs at the earliest site and the beginning of the QRS complex of clinical PVCs (PVC earliest EGM-ECG) was also noted. The value of Cath EGM-ECG as a reference for procedural success of ablation was evaluated by examining the relationship between Cath EGM-ECG and PVC earliest EGM-ECG. Results Fifty-two patients had successful ablation, and 43 of them (82.7%) had PVC earliest EGM-ECG values greater than or equal to Cath EGM-ECG. Eleven patients had procedural failure, and all of them had PVC earliest EGM-ECG values lower than Cath EGM-ECG (Table 1). A PVC earliest EGM-ECG value -1.5 ms greater than Cath EGM-ECG predicted successful ablation with a sensitivity of 90.4% and a specificity of 100.0% in the general patient population (Figure 1). Conclusion The results of the present study indicate that catheter-induced PVCs generated at the site of the presumptive source of origin of clinical PVCs may guide the timing of the earliest site during clinical PVC ablation. Further studies are required to validate our results and test the predictive value of Cath EGM- ECG interval for long-term success of PVC ablation. Table 1 PVC earliest EGM-ECG < Cath EGM- ECG PVC earliest EGM-ECG ≥ Cath EGM- ECG Ablation successful (n:52) 9 (17.3%) 43 (82.7%) Ablation not successful (n:11) 11 (100.0%) 0 (0%) Outcome of ablation in general patient population according to the relationship between PVC earliest EGM-ECG and Cath EGM- ECG Abstract Figure 1

Determination of optimal time for reading of rapid urease test diagnosis of Helicobacter pylori.

The study aimed to find the best reading time for the best accuracy of RUT in optimal time to obtain faster results with lower false rates and consequently save time in commencing treatment of peptic ulcers. Rapid urease test is well known to be an accurate test for H.pylori detection in tissue biopsies. Patients with GI problems referring to a university hospital in Tehran who underwent endoscopy and biopsy were entered in the project and three samples of mucosal tissue were captured from the lesser curvature, the antrum and the body of stomach. We found 39.6% sensitivity and 95% specificity for the named test in the first 5 minutes as well as PPV = 95.5% and NPV = 37.3% while the accuracy was 54.79%. Except for the specificity which was constantly 95% in all RUT reading times, other diagnostic parameters increased as time went on. The PPV was also higher than 97% after 10 minutes. The highest values of sensitivity, specificity, PPV, NPV and accuracy were achieved after 12 hours including 88.7%, 95%, 97.9%, 76% and 90.41%, respectively. To conclude, it seems that there are many different ideas with respect to the rapid urease test in H.pylori detection. However, the current study recommends reading the test optimally after 12 hours but it is suggested more multidisciplinary studies with bigger sample size be carried out to obtain better and more reliable results to be able to generalize in this regard.

Novel transcatheter therapies for treating tricuspid regurgitation

Until recently, tricuspid valve (TV) disease has been relatively neglected for a long time, but recently tricuspid regurgitation (TR) has attracted attention. Although the prognosis of patients with these disorders is poor, the high mortality and morbidity associated with TV surgery have resulted in many patients not receiving surgical therapy. Current guidelines recommend that TV surgery should be considered in patients with severe TR who are symptomatic or have progressive right ventricle (RV) dilatation or dysfunction. In the absence of severe RV or left ventricle dysfunction, surgery should be considered in cases of severe pulmonary vascular disease or hypertension; however, it is difficult to assess RV dysfunction. Symptoms of right heart failure are more nonspecific and difficult to diagnose than those of left heart failure. Furthermore, the severity of TR is easily influenced by the use of diuretics. These factors lead to difficulties in patient selection and in determination of optimal timing for surgery. Transcatheter therapies for TR have begun to emerge as an alternative for patients with severe symptomatic TR who are at high-risk for standard surgery. Although initial results from a recent international multicenter registry have demonstrated that transcatheter TV therapy is feasible and safe, its clinical experience is still under development. In the present review, we describe the currently available techniques of transcatheter TV intervention and preliminary clinical results.

Myelofibrosis: to transplant or not to transplant?

Hematopoietic cell transplantation (HCT) is the only curative therapeutic modality for myelofibrosis (MF) at present. The optimal timing of HCT is not known in the presence of wider availability of less risky nontransplant therapies such as JAK 1/2 inhibitors. Careful review of patient, disease, and transplant-related factors is required in the appropriate selection of HCT vs the best available nontransplant therapies. We highlight some of the relevant issues and positioning of HCT in light of evolving data on JAK 1/2 inhibitors. The goal of this study is to provide the reader with updated evidence of HCT for MF, recognizing that knowledge in this area is limited by the absence of comparative studies between HCT and nontransplant therapies. Prospective studies are needed for better information on: the determination of optimal timing and conditioning regimens, the best way to integrate JAK inhibitors in the HCT protocols, and the impact of JAK inhibitors on graft-versus-host disease.

Selection of event tickets for bundling in sports and entertainment industry

Most sports and entertainment firms offer season tickets first, and they allow purchasing single tickets at a later date. Basic decision problems within this context are the determination of optimal time at which switch from bundled tickets to single tickets should occur and the decision of which event tickets to include into the bundle. In this paper we focused on the second decision problem. For a given schedule of events, where ticket demands follow a Poisson Process, the tickets of a certain number of events are bundled and a discount is applied to the prices of these bundled tickets, with the aim of increasing total revenue. We find increase and decrease patterns in total revenue as the time slots of bundled events vary. With the help of these patterns, we develop a heuristic approach that creates easy-to-use business rules for the selection of profitable bundles for a given schedule.

Computational Model for Determination of Optimal Timing of Delivery in an Obese Population

Computational Model for Determination of Optimal Timing of Delivery in an Obese Population

Determination of optimum timing for chemical control of cutworms Agrotis spp. (Lepidoptera, Noctuidae) using light traps and pheromone traps

Determination of optimum timing for chemical control of cutworms Agrotis spp. (Lepidoptera, Noctuidae) using light traps and pheromone traps

1489 PUBLICATION Determination of optimal times of delivery for improved acute tolerability of 5-fluorouracil, oxaliplatin and carboplatin in colorectal or lung cancer patients

1489 PUBLICATION Determination of optimal times of delivery for improved acute tolerability of 5-fluorouracil, oxaliplatin and carboplatin in colorectal or lung cancer patients

193 EVALUATION OF A NOVEL ELECTRONIC ESTRUS DETECTION DEVICE IN RECIPIENTS SYNCHRONIZED FOR EMBRYO TRANSFER

The ability to detect estrus in cattle is an important aspect for both successful artificial insemination (AI) and successful embryo transfer (ET). The use of estrus detection devices has allowed producers to more precisely determine when to breed their cattle. There have been many types of devices including chin-ball marking harnesses, dye patches, and even electronic devices that monitor the animal's activity. With the growing popularity in timed AI and ET, these devices have again become of great interest. The latest tool for estrus detection is the multi-use TattleTale" Heat Detector (Microdyne Co., LLC., St. Joseph, MO, USA). The TattleTale" is an electronic device that is placed in a patch and affixed to the tail head. It is activated by a 3-s mount with subsequent mounts recorded per h through 12 h. Twelve hours after activation the device flashes indicating that the animal is ready for breeding. Such devices may allow breeders to determine exactly when estrus began as well as identify the peak estrus period, resulting in more accurate determination of optimal time for AI or ET. The objective of this study was to compare the accuracy of estrus detection devices when analyzing detection records and pregnancy rates. Cows from the Dixon Springs Agricultural Center (Simpson, IL, USA) were randomly separated into two groups based on estrus detection devices, one group receiving Kamar� patches (Kamor, Inc., Steamboat Springs, CO, USA) and the other receiving TattleTales. Both groups were synchronized using the OvSynch protocol (Syntex, Buenos Aires, Argentina). Cows were checked twice each day for four consecutive days, with a fifth day occurring a week later when the embryos were transferred. Estrus results were analyzed using a PROC UNIVARITE and GLM analyses with differences between treatment means determined by the LSD method of SAS (SAS Institute, Inc., Cary, NC, USA). The TattleTale detected a higher percentage (P < 0.05) of the cows in estrus (92 vs. 70%) than the Kamar� patch. Further, the TattleTale detected more asynchronous recipients (in estrus >48 h before expected) and synchronous recipients (in estrus <24 h than expected), although not significant with this sample size. In the present study, the TattleTale was more accurate in detecting estrus (i.e. fewer pregnancies were observed without estrus detected). Using the TattleTale information, a breeder would be able detect more animals in estrus and determine the most accurate time to breed or transfer embryos. Practically, the use of estrus detection devices in combination with timed AI and ET could allow for the exclusion of animals not in estrus in the optimal time windows for AI or ET, thus saving valuable semen and embryos that would be otherwise wasted on asynchronous females. The advantages of this device to producers include improved pregnancy rates based on timed breeding, lower herd management costs due to reduced quantities of wasted semen or embryos and fewer cows being resynchronized. This device also records any mounting activity missed by visual observation alone. This work was supported by USDA RRF W-1171.

Investigations on skeletal growth zones via bone scans as base of determination of optimal time for surgery in mandibular asymmetry

AIM of the study was to find out wether there is a common stop of growth of mandibular bone, so that no individual determination of the optimal time for surgery in patients with asymmetric mandibular bone growth is needed. As there are no epiphyseal plates in the mandibular bone, stop of growth cannot be determined on X-ray films. Bone scans of 731 patients [687 patients (324 male, 363 female) under 39 y for exact determination of end of growth and 44 (21 male, 23 female) patients over 40 y for evaluation of non-growth dependent differences in tracer uptake] were reviewed for the study. All the patients were examined 3 hours after injection of 99mTc-DPD. Tracer uptake was measured by region of interest technique in different points of the mandibular bone and in several epiphyseal plates of extremities. Tracer uptake in different epiphyseal plates of the extremities shows strong variation with age and good correlation with reported data of bone growth and closure of the epiphyseal plates. The relative maximum of bone activity is smaller in mandibular bone than in epiphyseal plates, which show well defined peaks, ending at 15-18 years in females and at 18-21 years in males. In contrast, mandibular bone shows no well defined end of growing but a gradually reduction of bone activity which remains higher than bone activity in epiphyseal plates over several years. No well defined end of growth of mandibular bone exists. The optimal age for surgery of asymmetric mandibular bone growth is not before the middle of the third decade of life, bone scans performed earlier for determination of bone growth can be omitted. Bone scans performed at the middle of the third decade of life help to optimize the time of surgical intervention.

Determination of optimal timing of peripheral blood progenitor-cell collection in children

Determination of optimal timing of peripheral blood progenitor-cell collection in children

Effect of Flow Diversions on Contaminant Transport Modeling in the Niagara River

A numerical model is formulated to simulate one-dimensional transport of a conservative tracer through the Niagara River, from Fort Erie to Niagara-on-the-Lake. The model accounts for flow splits at Grand and Navy islands and, more significantly, incorporates the operations of the New York Power Authority and Ontario Hydropower. These involve large-scale diversions and temporary storage of water for power production, resulting in a dispersion-like effect on the breakthrough curves for the tracer at Niagara-on-the-Lake. In comparison with straight through-flow calculations, the model results indicate an increase in mean residence times by up to 25% and decreases in peak concentrations by up to 50%, depending on the time of day the contaminant release occurs. In addition, the model shows the distribution of tracer mass remaining in the system after a typical sampling program, as currently followed in the Niagara River Toxics Management Plan. This allows a determination of optimal timing for sampling in order to maximize mass recovery. The model provides a tool to help understand transport in this complex hydraulic system.

REMOTE SENSING IN THE SOLUTION OF SCIENTIFIC AND ECONOMIC PROBLEMS IN CUBA

Remote sensing inventories of the land and marine resources of Cuba, both from satellite and aerial platforms, are assessed in terms of their contributions to research on the country's physical and economic geography. Under the auspices of an international cooperative program “Interkosmos,” maps of many types have been upgraded, the costs of surveys have been reduced dramatically, and the potential for monitoring natural and human-induced change is being realized more fully. In addition, a study of weather and other conditions affecting image quality led to a determination of optimal times for conducting remote sensing surveys. Translated from: Vestnik Moskovskogo Universiteta, geografiya, 1988, No. 3, pp. 36-41, by Edward Torrey, Alexandria, VA 22308.

Effects of various hormone treatments on induction of lactation in the ewe.

In Exp. I and II, 52 of 68 ewes were induced into lactation with twice-daily injections of estradiol-17 beta (E2-beta) and progesterone (P4; .5 and 1.25 mg/kg body weight/day) for 7 days. Additional treatments were twice-daily injections (days 18 to 20) of hydrocortisone, growth hormone, thyroxine and thyrotropin releasing hormone alone or in various combinations. In Exp. III, 12 ewes were induced into lactation. In this experiment, all ewes were injected with E2-beta and hydrocortisone, as previously, but four ewes (III-2) had P4 injections extended to day 20, and four ewes (III-3) were not injected with P4. Across experiments, lowest milk yields during lactation and the lowest percentage of ewes induced into lactation (58%) occurred when only E2-beta and P4 were injected. Inclusion of hydrocortisone injections (50 mg/day) induced the highest percentage of ewes into lactation (86%, 38 of 44), the highest peak daily yields of milk and the highest total yields during lactation. Including injections of growth hormone, thyroxine or thyrotropin releasing hormone alone or in combinations did not produce better results than injections of E2-beta and P4 alone. Injections of E2-beta and hydrocortisone without concurrent injections of P4 were less effective. Intramuscular injections of P4 (10 mg/day) from days 8 to 20 did not inhibit lactogenesis or subsequent lactation. Across all experiments, 76% of multiparous (52/68) and 50% of nulliparous (6/12) ewes produced greater than 100 ml milk/day during their lactation (34 to 95 days). However, yields of milk for ewes that lactated were only 25 to 50% of those from postpartum ewes. The importance of including injections of hydrocortisone in the induction procedure was established, but determination of optimum time to inject and potential importance of other hormones requires additional research.

Determination of Optimum Time and Temperature for the Reaction of Selected Conjugated 3-Ketosteroids with Isonicotinic Acid Hydrazide Reagent

Abstract The reaction of selected conjugated 3-ketosteroids with isonicotinic acid hydrazide (INH) reagent in methanol was investigated. The Δ1, 4−3-ketosteroids differed considerably from the Δ4 -3-ketosteroids with regard to the wavelength of maximum absorbance and to the reaction time and temperature required to attain maximum absorbance readings. Optimum conditions resulting in stable, maximum absorbance readings were determined experimentally for 17 standard compounds.