Time Period Research Articles

Extraction of geraniol from palmarosa oil using hydrotropic solvents

The extraction of geraniol from palmarosa oil using hydrotropic solvents was investigated. Palmarosa oil possesses an appealing rose aroma and properties like anti-inflammatory, antifungal, and antioxidant due to the presence of geraniol. The extraction of geraniol from palmarosa oil by using distillation methods like steam distillation and fractional distillation was a laborious process. So hydrotropes were tried for extraction. The geraniol yield and purity depend on parameters like concentration of hydrotrope, solvent volume ratio, and time period. Using the Box Benkhem Design (BBD), the extraction process was optimized. One of the major advantages of using hydrotropic solvents is that they were classified as green solvents, and recovery of solvents is also possible. To reduce the extraction time probe sonication is carried out. Different hydrotropic solvents with probe sonication are done on palmarosa oil by altering various process parameters to study the separation, yield, and purity.

Changes in attitudes, beliefs, and experiences related to pregnancy during graduate medical education training from 2005 to 2021.

Today, 50% of medical students are women, and residency and fellowship training years overlap with peak times for starting families. The authors describe attitudes toward pregnancy during residency and fellowship and report pregnancy rates and complications for female residents and resident partners across several decades. A web-based survey was emailed to 1,057 residents in 2005 (period 1) and 1,860 residents in 2021 (period 2). Anonymous surveys were sent to all trainees including pregnant trainees, affected co-trainees and trainee partners. Resident attitudes and pregnancy characteristics were compared between groups using the chi-square (χ2) test for categorical variables and the Kruskal-Wallis test for ordinal variables. A total of 442 residents (41.8%) responded to the 2005 survey, and 525 (28.2%) responded to the 2021 survey. Most residents who covered for a pregnant resident had positive feelings about covering for their colleagues during both time periods, although more positive attitudes were present during the period 2. Only about 10% of residents received compensation for their coverage during both time periods. Among residents with a pregnancy during training (i.e., themselves or partners), most characterized having a baby in training as "somewhat difficult" or "very difficult" at both time periods. Pregnancy complication rates were 33% and 44% for training years 2005 and 2021. As medical education evolves, training programs should be proactive in creating structured support systems for pregnant residents and resident partners to minimize adverse maternal and fetal outcomes and to improve training programs. Future studies are needed to elucidate the causality of higher-than-expected pregnancy complication rates.

The economic benefit of herd genotyping and using sexed semen for pure and beef-on-dairy breeding in dairy herds.

The cost benefits of herd genotyping and the benefits of using sexed semen have been affected by recent improvements in sexing technologies, the incorporation of direct health traits in the German total merit index for Holstein cattle, the deteriorating prices for purebred heifer calves and bull calves, and the introduction of herd genotyping programs. Inseminating the genetically superior dams with female-sexed Holstein semen increases the mean breeding value of the heifer calves and can produce more Holstein heifer calves than are needed for replacement. This provides an opportunity to increase the selection response in health and production traits at the farm level. A deterministic model is introduced that predicts the increase or decrease in net profit when a farmer takes part in a herd genotyping program and follows a certain insemination strategy. The types of semen that are allocated to cows and heifers are sexed semen or unsexed semen and Holstein semen or beef breed semen. The genetically superior heifers and cows are inseminated with female-sexed Holstein semen, intermediate dams with unsexed Holstein semen, and genetically inferior dams with unsexed or male-sexed beef breed semen. In general, participating in a herd genotyping program is beneficial for German Holstein breeders. The optimum proportions of cows and heifers that should be inseminated with a certain type of semen are sensitive to farm-specific peculiarities. A small price difference between crossbred bull calves and crossbred heifer calves often makes the use of male-sexed beef breed semen uneconomic. Under the conditions considered, it was found to be advantageous to inseminate approximately 50% of the heifers and 10% of the cows with the highest genetic merit with female-sexed Holstein semen. The optimum proportion of cows that should be inseminated with unsexed beef breed semen was found to be approximately 40%. In a herd with a low replacement rate, the selected heifers can exhibit their genetic superiority over a longer period of time, and a larger proportion of cows can be inseminated with beef breed semen. Participation in a herd genotyping program is, therefore, particularly beneficial for herds with low replacement rates.

Three-dimensional copula framework for early warning of agricultural droughts using meteorological drought and vegetation health conditions

ABSTRACT This study develops an early warning system for crop yield (CY) failure based on meteorological drought and vegetation health conditions. The framework combines three drought indices – the Standardized Precipitation Evapotranspiration Index (SPEI), standardized Normalized Difference Vegetation Index (stdNDVI), and standardized CY (stdCY) values – using copulas. Datasets for five major wheat-producing cities in Turkey between 2000 and 2022 are used for analysis. Results indicate that the time periods used to calculate SPEI and NDVI are critical in determining agricultural drought and CY conditions. The critical threshold values for SPEI and NDVI, with a 10% probability of causing agricultural drought, are found to be ~0.28 and ~0.42, respectively. Using a three-dimensional copula model resulted in more precise CY simulations than a two-dimensional model. The validation efforts showed that all of the observed CYs fell within the simulated range, indicating the robustness of the methodology in capturing drought impacts on CY conditions.

Perioperative Antibiotic Prophylaxis—Indications and Modalities for the Prevention of Postoperative Wound Infection.

Postoperative surgical site infections (SSI) account for almost 25% of all nosocomial infections in Germany and are a source of increased morbidity and mortality. This review is based on pertinent publications retrieved by a selective search in PubMed and on national and international guidelines. The individual risk factors for SSI must be assessed before any surgical procedure. A body-mass index above 30 kg/m2 is associated with an unadjusted risk ratio of 1.35 [1.28; 1.41] for SSI, which rises to 3.29 [2.99; 3.62] if the patient is also immunosuppressed. The risk of SSI is also significantly higher with certain types of procedure. Perioperative antibiotic prophylaxis (PAP) is clearly indicated for operations that carry a high risk of SSI (e.g., colorectal surgery) and for those that involve the implantation of alloplastic material (e.g., hip endoprostheses). PAP can usually be administered with basic antibiotics such as cefazoline. The basic principles of PAP are that it should be given by the anesthesia team in the interval from 60 minutes preoperatively up to shortly before the incision, and that its administration should only be for a short period of time, usually as a single shot. Continuing PAP onward into the postoperative period leads to increased toxicity, bacterial superinfections, and antibiotic resistance. The evidence shows that perioperative antibiotic prophylaxis is a component of a bundle of measures that can help prevent SSI. Strict indications and adherence to the basic principles of PAP are essential for therapeutic success.

Low Rate of Asymptomatic Dengue Infection Detected in Coastal Kenya Using Pooled Polymerase Chain Reaction Testing.

Asymptomatic dengue virus (DENV) infections have important public health implications but are challenging to identify. We performed a cross-sectional study of reverse transcription quantitative polymerase chain reaction on pooled sera of asymptomatic individuals from the south coast of Kenya at two time periods to identify cases of asymptomatic viremia. Among 2,460 samples tested in pools of 9 or 10, we found only one positive case (0.04% incidence). Although pooling of samples has the potential to be a cost-effective and time-efficient method for asymptomatic DENV detection, mass cross-sectional pooled testing may not provide accurate data on rates of asymptomatic infection, likely owing to a decrease in the sensitivity with pooling of samples, a short period of viremia, or testing in the absence of an outbreak.

Curcumin as a Potential Phytoconstituent used for Cancer Treatment: An Overview

Background:: Cancer is one of the leading causes of death worldwide. Therapy for cancer has remained a challenge for a very long period of time, though developments of various treatment strategies have been introduced. However, Curcuma longa L (Turmeric) attains major attention to cure cancer due to its phytoconstituents which can be used in the treatment of various cancers. Due to the wide availability and minimal adverse effects, curcumin has become a source of significant interest in research for cancer treatment which can lead to heavy cost cut off in the treatment. Objective:: In this review article, the anti-cancer properties of curcumin in the treatment of cancer are highlighted. Conclusion:: Scientists from all over the world have been interested in curcumin, a polyphenol isolated from Curcuma longa, for its biological properties, the most well-known of which is its ability to fight cancer. It is one of the most promising classes of bioactive natural substances, particularly in the treatment of various cancer types. Curcumin demonstrates anticancer properties. To overcome the limitation of curcumin numerous studies, analysis, and research has been already completed and many are still going on. The use of curcumin either alone or in combination might alter the treatment of cancer.

Fuzzy expert system design for detecting stunting

Stunting is a chronic nutritional problem that occurs in toddler due to lack of nutritional intake which results in impaired growth toddler. Usually, toddler who experience stunting are characterized by not increasing weight over a long period of time. Application utilization health which makes it easier for users to access information, one of which can be used to identify toddler who are stunted by selecting symptoms. The symptoms experienced by toddlers go through a system known as the system expert. In this research an expert system will be developed that is capable of early detection developmental disorders in toddlers using the Mamdani fuzzy method. The results obtained from this research are an expert system design for early detection of stunting using the Mamdani fuzzy method. The Mamdani fuzzy method was implemented to group the criteria for toddlers who fall into the stunting category or not from the initial data which is still gray because they are still unsure whether to categorize the toddler as having stunting or not. The detection accuracy rate using the Mamdani fuzzy method is 80.87% compared to expert diagnosis.

Evolution of the obesity epidemic in the Spanish press: A comparative study 2000–05 and 2015–20

The present study aims to examine the treatment of obesity as an epidemic in the Spanish press during two different time periods. The first period is from 2000 to 2005 when obesity was declared an epidemic by the World Health Organization, the second period of study is from 2015 to 2020. For this study, a content analysis was made from a framing perspective. In the selected sample it was observed that the predominant frame in the two time periods changed. The frame of attribution of responsibility was the most used in the first period and the frame of conflict in the second. Variations in the use of frames were also observed depending on the newspaper, the year of publication, the subject matter and the subjects involved.

Sliding-window cross-correlation and mutual information methods in the analysis of solar wind measurements

Context. When describing the relationships between two data sets, four crucial aspects must be considered, namely: timescales, intrinsic lags, linear relationships, and non-linear relationships. We present a tool that combines these four aspects and visualizes the underlying structure where two data sets are highly related. The basic mathematical methods used here are cross-correlation and mutual information (MI) analyses. As an example, we applied these methods to a set of two-month’s worth of solar wind density and total magnetic field strength data. Aims. Two neighboring solar wind parcels may have undergone different heating and acceleration processes and may even originate from different source regions. However, they may share very similar properties, which would effectively “hide” their different origins. When this hidden information is mixed with noise, describing the relationships between two solar wind parameters becomes challenging. Time lag effects and non-linear relationships between solar wind parameters are often overlooked, while simple time-lag-free linear relationships are sometimes insufficient to describe the complex processes in space physics. Thus, we propose this tool to analyze the monotonic (or linear) and non-monotonic (or non-linear) relationships between a pair of solar wind parameters within a certain time period, taking into consideration the effects of different timescales and possible time lags. Methods. Our tool consists of two parts: the sliding-window cross-correlation (SWCC) method and sliding-window mutual information (SWMI) method. As their names suggest, both parts involve a set of sliding windows. By independently sliding these windows along the time axis of the two time series, this technique can assess the correlation coefficient (and mutual information) between any two windowed data sets with any time lags. Visualizing the obtained results enables us to identify structures where two time series are highly correlated, while providing information on the relevant timescales and time lags. Results. We applied our proposed tool to solar wind density and total magnetic field strength data. Structures with distinct timescales were identified. Our tool also detected the presence of short-term anti-correlations coexisting with long-term positive correlations between solar wind density and magnetic field strength. Some non-monotonic relationships were also found. Conclusions. The visual products of our tool (the SWCC+SWMI maps) represent an innovative extension of traditional numerical methods, offering users a more intuitive perspective on the data. The SWCC and SWMI methods can be used to identify time periods where one parameter has a strong influence on the other. Of course, they can also be applied to other data, such as multi-wavelength photometric and spectroscopic time series, thus providing a new tool for solar physics analyses.

The longitudinal risk of hemorrhage of melanoma brain metastases after Gamma Knife radiosurgery.

The objective of this study was to analyze the hemorrhagic risk of melanoma brain metastases after Gamma Knife radiosurgery (GKRS). A prospective institutional database was retrospectively queried to identify patients who underwent GKRS for melanoma brain metastases between 1990 and 2021. Lesional hemorrhage was defined as definite or possible based on radiologists' readings, and severity was graded according to Common Terminology Criteria for Adverse Events. Two hundred ninety-one patients with 1083 lesions treated in 419 sessions were identified. The mean (± SD) patient age was 60 ± 15 years, and 61% were male. The median follow-up period for overall survival (OS) was 11 (range 0-214) months with 581 patient-years. Definite/possible lesional hemorrhages occurred in 13% of lesions, with grade 3 hemorrhages observed in 4% of lesions. Surgical intervention was required in 2% of cases (5% of patients), and all resected lesions were pathologically consistent with melanoma. A decreased risk of definite/possible lesional hemorrhage was associated with a later time period between 2015 and 2021 (OR 0.45, 95% CI 0.266-0.75, p = 0.0021), increased marginal dose (OR 0.91, 95% CI 0.83-0.99, p = 0.037), antiplatelet use post-GKRS (OR 0.195, 95% CI 0.083-0.46, p < 0.001), and whole-brain radiotherapy (WBRT; OR 0.53, 95% CI 0.344-0.82, p = 0.0042). After 2015, more patients received anticoagulation, B-Raf proto-oncogene inhibitors, and immune checkpoint inhibitors, and fewer received bevacizumab (p < 0.001). The cumulative risk of lesional hemorrhage was 17%-20% at 36 months from GKRS, with 95%-96% of cases occurring within 12 months. The median patient OS was 11 (95% CI 9-13) months, and multivariate Cox regression analysis revealed that antiplatelet agents (hazard ratio [HR] 0.66, 95% CI 0.45-0.96, p = 0.031) and immune checkpoint inhibitors (HR 0.35, 95% CI 0.26-0.48, p < 0.001) were associated with longer OS, while WBRT (HR 1.36, 95% CI 1.02-1.81, p = 0.037) and definite/possible hemorrhage (HR 1.39, 95% CI 1.04-1.85, p = 0.024) were associated with shorter OS. The definite hemorrhage risk of melanoma brain metastases after GKRS was 17% in the first 3 years and 95% of the lesional hemorrhage occurred within the 1st year. Surgical intervention was needed in 5% of patients. Antiplatelet agents and immune checkpoint inhibitors were associated with improved OS, while definite/possible hemorrhage was associated with worse OS.

A New Visible Spectrophotometric Approach for Determination of Methyldopa in Pharmaceuticals

الهدف من البحث هو تطوير طريقة طيفية جديدة لتقدير عقار الميثيل دوبا بشكليه النقي والصيدلاني تعتمد الطريقة المقترحة على التفاعل بين المثيل دوبا و كاشف الانسدين بوجود نيتروبروسيد البوتاسيوم وهيدروكسيد الصوديوم لتكوين ناتج ملون تم دراسة تأثير العديد من العوامل المؤثرة على ناتج التفاعل تتضمن تركيز الكاشف و زمن التفاعل و استقرارية الناتج الملون مع ضبط هذه العوامل. متابعة التفاعل تمت بقياس الامتصاص عند 597 نانومتر للناتج الملون. في مدى من التركيز من (0.50 إلى 80.0) ميكروغرام.مل -1 كانت حساسية ساندل 0.0218 مايكروغرام.سم-1 و حد الكشف 0.0353 مايكروغرام.مل-1 و الحد الكمي 0.2691 مايكروغرام.مل-1. تم تطبيق الطريقة المقترحة بنجاح لتقدير المثيل دوبا في المستحضرات الصيدلانية.

A FEA-Based Fast AC Steady-State Algorithm for a Voltage-Driven PMSM by a Novel Voltage-Flux-Driven Model

Finite element analysis (FEA) has been used more frequently than ever before in electrical machine design covering different disciplines such as electromagnetics, rotor dynamics, thermodynamics etc. The accuracy and speed of FEA are in high demands, especially when the time-stepping FEA is employed in the electromagnetic design of the machine. In this paper, to accelerate numerical transient in FEA of a voltage-driven permanent magnet synchronous machine (PMSM), a fast AC steady-state algorithm has been proposed, in which the voltage supply is converted into the stator flux linkage and the machine can be regarded as driven by the flux linkage directly. The electromagnetic transient is eliminated by injecting additional voltage signals to compensate the oscillating stator flux linkage in transient and the time-stepping error caused by the backward Euler in FEA. And the additional voltage signals will finally disappear after the steady state is achieved within about a half electrical time period. In addition, the maximum torque per ampere (MTPA) control logic can also be realized by adjusting the initial phase angle of the voltage supply based on the vector diagram. The simulation speed of the proposed method in this paper was compared to other traditional models and the accuracy was verified by experimental results.

Variation in Muskox (Ovibos moschatus) Guard Hair Growth Rates: Implications for Measuring Chronological Biomarkers.

Segmental analyses of hair may be useful for measuring biomarkers over several seasons to years from a single sample. To attribute hair segments to specific time periods, a known chronological marker, or a hair growth rate, is needed. We examined guard hair growth rates of captive muskoxen (Ovibos moschatus) in Fairbanks, Alaska, USA. We sought to determine if a general growth rate could be applied across muskox populations, thus facilitating the use of segmental analyses for various biomarkers. We used archived samples from 16 muskoxen that had guard hairs sampled at six, 14, and 30 wk after shaving. We measured the lengths of 10 guard hairs per sample, calculated weekly and annual growth rates, and then fitted linear mixed-effects models to assess the effect of different covariates on hair growth rate. The period in which hair had been grown had a significant effect (P<0.05) on growth rate. Extrapolated annual hair growth rates were 277±40 mm/yr (weeks 0-6), 248±47 mm/yr (weeks 7-14), and 165±36 mm/yr (weeks 15-30), with an overall average rate of 210±14 mm/yr. These rates were significantly faster than those of free-ranging Greenland muskoxen-78 mm/yr as measured by stable isotope analyses-and varied intra-annually. This suggests that a universal growth rate cannot be generalized across muskox populations and time.

Identifying clusters of patient comorbidities associated with obstructive sleep apnea using electronic health records.

The objectives of this study were to understand the relative comorbidity burden of obstructive sleep apnea (OSA), determine whether these relationships were modified by sex or age, and identify patient subtypes defined by common comorbidities. Cases with OSA and noncases (controls) were defined using a validated electronic health record (EHR)-based phenotype and matched for age, sex, and time period of follow-up in the EHR. We compared prevalence of the 20 most common comorbidities between matched cases and controls using conditional logistic regression with and without controlling for body mass index. Latent class analysis was used to identify subtypes of OSA cases defined by combinations of these comorbidities. In total, 60,586 OSA cases were matched to 60,586 controls (from 1,226,755 total controls). Patients with OSA were more likely to have each of the 20 most common comorbidities compared with controls, with odds ratios ranging from 3.1 to 30.8 in the full matched set and 1.3 to 10.2 after body mass index adjustment. Associations between OSA and these comorbidities were generally stronger in females and patients with younger age at diagnosis. We identified 5 distinct subgroups based on EHR-defined comorbidities: High Comorbidity Burden, Low Comorbidity Burden, Cardiovascular Comorbidities, Inflammatory Conditions and Less Obesity, and Inflammatory Conditions and Obesity. Our study demonstrates the power of leveraging the EHR to understand the relative health burden of OSA, as well as heterogeneity in these relationships based on age and sex. In addition to enrichment for comorbidities, we identified 5 novel OSA subtypes defined by combinations of comorbidities in the EHR, which may be informative for understanding disease outcomes and improving prevention and clinical care. Overall, this study adds more evidence that OSA is heterogeneous and requires personalized management. Te TT, Keenan BT, Veatch OJ, Boland MR, Hubbard RA, Pack AI. Identifying clusters of patient comorbidities associated with obstructive sleep apnea using electronic health records. J Clin Sleep Med. 2024;20(4):521-533.

Futbolda Kaydedilen Gollerin Zaman Dilimlerine Göre Analizi: Beş Major Avrupa Ligi ve Türkiye Süper Liginin Değerlendirilmesi

Avrupa’nın beş majör ligi İngiltere PrmLig, Almanya BLiga, İspanya LaLiga, İtalya Serie-A ve Fransa Ligue-1 olarak kabul edilmektedir. Bu araştırmanın amacı, 2017-2018 futbol sezonunda Türkiye Süper Ligi ile 5 majör ligde kaydedilen gollerin analizini gerçekleştirmektir. Tslig (306), Bliga (306), Prmlig (380), Laliga (380), Ligue-1 (380) ve Serie-A'da (380) olmak üzere toplam 2132 maç analiz edildi. Sezon boyunca tüm Avrupa liglerinde ve her bir lig özelinde kaydedilen toplam ve ortalama gol değerleri, maçın ilk ve ikinci yarılarında, 15 dakikalık klasik zaman dilimlerinde ve uzatma dakikalarında kaydedilen goller (45dk+ ve 90dk+) kayıt altına alındı. Tanımlayıcı istatistik kullanılarak ortalama, frekans ve yüzde dağılımları ortaya konuldu. Ligler arası analizler için Kruskal Wallis testi uygulandı. Gruplar arası fark varsa Bonferroni düzeltmesi yapılarak Dunn Testi gerçekleştirildi. Araştırmanın sonucunda; TsLig (906gol), BLiga (855gol), PrmLig (1018gol), LaLiga (1024gol), Ligue-1 (1017gol) ve Serie-A’da (1033 gol) olmak üzere toplam 5853 gol kaydedildi. Gol ortalamasının en yüksek olduğu ligin TsLig olduğu tespit edilirken (2,96/maç); Gollerin %56’lık bölümü maçların ikinci yarılarında gerçekleşmiştir (p&amp;lt;0.001). Klasik periyotlamalara göre en fazla gol ise 76 dk - maç sonu diliminde gerçekleşmiştir (%23). Liglerin tümünde gollerin %7,4’lük bölümü ilk ve ikinci devrelerin uzatma dakikalarında atıldı (413gol). Türkiye Süper Ligi 100 gol ile hem her iki devrenin sonlarında hem de uzatma dakikalarının toplamında en çok gol kaydedilen lig oldu. Bu durum özellikle oyuncuların fiziksel kapasitelerinin yetersizliğine ve maç sonunda olası konsantrasyon kayıplarına bağlanabilir.

Development of the United States’ University tenure system from the perspective of the protection of teachers’ rights and interests

As a fundamental system for protecting the rights and interests of teachers, the university tenure system plays a crucial role in the development of universities in the United States. The tenure system has developed and evolved over a long period of time, from the dual track system of university teachers under church management in the 17th century to the formal establishment of the university tenure system in the 20th century and then to the “up-or-out” policy in the 21st century. The foundation of this system’s development has always been maintaining teachers’ academic freedom and guaranteeing their livelihoods. This article explores how universities and related institutions in the United States have integrated the protection of teacher academic freedom and economic security throughout the development of higher education by studying the development of the US university tenure system.

An Approach to the Performance of Passport Services through Workload and Work Environment: Study at the Wonosobo Immigration Office

This study aims to identify the effect of workload and work environment on the performance of passport issuance services at the Wonosobo Immigration Office. Workload is defined as a series of tasks that must be carried out by a work unit within an organization or by an individual who serves in a position within a certain period of time. Meanwhile, the work environment is defined as a place where a worker completes his duties in accordance with the goals to be achieved. There is a mismatch in the number of human resources in passport services compared to the high level of passport applications. The research method used in this research is quantitative method. Data collection was carried out through observation and distribution of questionnaires. Sampling using total sampling techniques, and data analysis was carried out using a Likert scale. The data analysis technique applied in this study is using multiple linear regression data analysis techniques. The results of data collection show the significance of workload of 0.32 and work environment of 0.21 greater than 0.05, which means that there is an influence of workload and work environment on employee performance in passport services. This study recommends increasing the number of human resources and improving the work environment to improve the performance of passport issuance services.

Immobilization: the promising technique to protect and increase the efficiency of microorganisms to remove contaminants

AbstractBiodegradation of pollutants is one of the most economical methods for their removal and usually is accompanied by no production of toxic by‐products. In general, this approach is favored over others because it offers reduced expenses and the potential for complete mineralization. In order to enhance the viability and longevity of the bioremediation agents within polluted areas, it becomes necessary to immobilize the cells. Cell immobilization refers to the procedure of confining intact cells to specific areas within a device or material, without compromising their essential biological functions. A wide variety of carriers and approaches have been used for the restriction of various cells. Immobilization techniques, such as microencapsulation, have opened up new possibilities in biotechnology by facilitating the development of artificial organs, cell therapies and drug delivery systems. Researchers have found promising outcomes in various applications through the immobilization of microorganisms. This approach enhances stability, reusability and catalytic efficiency, making immobilization a valuable strategy for biocatalysis, bioremediation and other biotechnological processes. Notably, the use of immobilized microorganisms has led to significant improvements in the removal of pollutants, with some studies achieving 100% efficiency. When comparing the degradation of pollutants between free and immobilized microorganisms over the same time period, the results demonstrated that immobilized microorganisms achieved a removal efficiency &gt;21% more than that of free microbial consortia. The primary objective of this review is to give an overview of the key scientific aspects related to bioremediation of various pollutants using immobilized cells, with a particular focus on the techniques used to entrap the cells. © 2024 Society of Chemical Industry (SCI).

A GEOGRAPHICAL PERSPECTIVE ON THE IMPACT OF COVID-19 ON TOURISM DEMAND IN ROMANIA

Although the tourism sector has witnessed a gradual recovery during the last years from the devastating impact of the COVID-19 pandemic, it is still too soon to discuss about a full recovery, as territories have responded and adapted in diverse manners to the shock. As such, it is important to investigate the impact of the pandemic in different moments and at different geographical scales, in order to identify and understand the contrasts between territories of same countries. In light of these facts, the purpose of the current paper is to assess the evolution and the spatial patterns of tourism demand in Romania under the impact of the COVID-19 pandemic for the period of time 2020-2023. The focus is on identifying the differences between regions and destinations in terms of initial impact of the pandemic and of their path to recovery to pre-pandemic levels of tourist arrivals.