Investigation of the effects of Theranekron and Sorafenib treatments on carcinogenesis, apoptosis and biochemical profile in hepatocellular carcinoma in rats.

This study aimed to investigate the effects of Tarantula cubensis alcohol extract (TCAE, Theranekron) and Sorafenib (S) treatments on carcinogenesis, apoptosis and biochemical profile of rats with experimentally induced hepatocellular carcinoma (HCC). In the presented study, 58 male rats were divided into 7 groups; Negative Control (NC, n = 6), NC + TCAE (NCT, n = 6), NC + Sorafenib (NCS, n = 6), Positive Control (PC, n = 10), Positive Control + TCAE (PCT, n = 10), Positive Control + Sorafenib (PCS, n = 10), Positive Control + TCAE + Sorafenib (PCTS, n = 10). The active ingredients Diethylnitrosamine (DEN, 120 mg/kg, single dose) and Nitrosomorpholine (NMOR, 50 ppm, 21 weeks orally) were used to induce HCC in rats. At the end of the experiment, the animals were euthanized under appropriate conditions and samples were collected for biochemical and pathological investigations. In the PC group, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) levels were higher (p < 0.001) and urea levels were lower (p < 0.001) compared to all other groups. Treatment groups reorganized the relevant markers (ALT, AST, GGT, and urea). A significant increase was detected in Caspase-10, Caspase-3 and Granzyme-B (GrzB) (p < 0.001) in blood and Caspase-10 and GrzB (p < 0.05) in liver tissue in PCT, PCS and PCTS groups compared to the PC group. Histopathological examination revealed that the PC group showed cancer morphology, and the treatment groups caused a decrease in tumor incidence and size. Our current findings suggest that the mechanism of action of TCAE in HCC is through the NKs/CTLs-GrzB-Casp10-Casp3 signaling pathway and can be used in combination with chemotherapy drugs for the development of future drug designs.

Eucalyptol regulates Nrf2 and NF-kB signaling and alleviates gentamicin-induced kidney injury in rats by downregulating oxidative stress, oxidative DNA damage, inflammation, and apoptosis.

Gentamicin, an aminoglycoside antibiotic, is nowadays widely used in the treatment of gram-negative microorganisms. The antimicrobial, anti-inflammatory, and antioxidant activities of eucalyptol, a type of saturated monoterpene, have been reported in many studies. The aim of this study was to examine the possible effects of eucalyptol on gentamicin-induced renal toxicity. A total of 32 rats were divided into 4 groups; Control (C), Eucalyptol (EUC), Gentamicin (GEN), and Gentamicin + Eucalyptol (GEN + EUC). In order to induce renal toxicity, 100 mg/kg gentamicin was administered intraperitoneally (i.p.) for 10 consecutive days in the GEN and GEN + EUC groups. EUC and GEN + EUC groups were given 100 mg/kg orally of eucalyptol for 10 consecutive days. Afterwards, rats were euthanized and samples were taken and subjected to histopathological, biochemical, immunohistochemical, and real-time PCR examinations. The blood urea nitrogen (BUN) and creatinine (CRE) levels were significantly decreased in the GEN + EUC group (0.76 and 0.69-fold, respectively) compared to the GEN group. The glutathione peroxidase (GPx) and catalase (CAT) activities were significantly increased in the GEN + EUC group (1.35 and 2.67-fold, respectively) compared to the GEN group. In GEN group, Nuclear factor kappa B (NF-kB), Interleukin 1-beta (IL-1ß), Inducible nitric oxide synthase (iNOS), Tumor necrosis factor-α (TNF-α), Caspase-3, 8-Hydroxy-2'-deoxyguanosine (8-OHdG) and Nuclear factor erythroid 2-related factor (Nrf2) expression levels were found to be quite irregular. GEN + EUC group decreased the expressions of NF-kB, IL-1ß, iNOS, TNF-α, Caspase-3, and 8-OHdG (0.55, 0.67, 0.54, 0.54, 0.63 and 0.67-fold, respectively), while it caused increased expression of Nrf2 (3.1 fold). In addition, eucalyptol treatment ameliorated the histopathological changes that occurred with gentamicin. The results of our study show that eucalyptol has anti-inflammatory, antioxidative, antiapoptotic, nephroprotective, and curative effects on gentamicin-induced nephrotoxicity.

When a balloon catheter or tenaculum is required for cervical traction during hysterosalpingography.

The aim of this study was to define the actual rate of the traction needed and the balloon catheter or tenaculum requirement for hysterosalpingography (HSG) examinations, and to investigate the correlation between pain scores with the type of traction, operator, parity or the type of infertility. 788 patients undergoing HSG participated in the trial. The HSG examinations were completed in 58% of the patients (458) without any traction. Traction was needed in 42% of patients, those with the balloon catheter in 26.9%, and those with the tenaculum only at 15%. Patients with balloon catheter traction had similar pain scores to those using tenaculum traction. The pain scores changed according to the operator. HSG examinations should be performed step-by-step and the need for traction evaluated during the procedure.IMPACT STATEMENTWhat is already known on this subject? HSG is a technique to evaluate fallopian tube patency and other potential intrauterine pathology in infertile women.What do the results of this study add? Traction was not needed in more than half of the HSG examinations. The pain due to the balloon catheter and tenaculum is similar.What the implications are of these findings for clinical practice and/or further research? HSG examinations should be performed step-by-step by checking the need for traction. Traction with the balloon catheter prevents the uterine spasm, infection and bleeding complications during or after the HSG.

Green's functions for a layered high-contrast acoustic media.

A parametric approach based on parametric analysis of the acoustical properties of a layered media is proposed to derive a reduced layered Green's function. The approach relies on the smallness of one of the problem parameters and allows a simpler form of Green's function by disregarding the smaller parametric terms. Several illustrative examples comparing the amplitudes of exact and reduced Green's function for small parameter of density ratio in various source and observation location setups are presented. It is demonstrated that the CPU times calculated at different points decrease considerably for the reduced Green's function, further justifying the presented method.

Channel Prediction for mmWave Ground-to-Air Propagation under Blockage.

Ground-to-air (GA) communication using unmanned aerial vehicles (UAVs) has gained popularity in recent years and is expected to be part of 5G networks and beyond. However, the GA links are susceptible to frequent blockages at millimeter wave (mmWave) frequencies. During a link blockage, the channel information cannot be obtained reliably. In this work, we provide a novel method of channel prediction during the GA link blockage at 28 GHz. In our approach, the multipath components (MPCs) along a UAV flight trajectory are arranged into independent path bins based on the minimum Euclidean distance among the channel parameters of the MPCs. After the arrangement, the channel parameters of the MPCs in individual path bins are forecasted during the blockage. An autoregressive model is used for forecasting. The results obtained from ray tracing simulations indicate a close match between the actual and the predicted mmWave channel.

Protective effects of nobiletin on cisplatin induced neurotoxicity in rats.

OBJECTIVES: This study was designed to investigate the possible antioxidant, antiapoptotic and neuroprotective effects of nobiletin on cisplatin-induced neurotoxicity rat model by evaluating neurotrophins, antioxidants and histopathology. METHODS: Forty male Wistar Albino rats were divided into four groups: control, cisplatin (CIS), cisplatin + nobiletin (CIS + NOB) and nobiletin + cisplatin (NOB + CIS). CIS + NOB was applied nobiletin (10 mg/kg, i.p.) during the last four days whereas NOB + CIS was applied nobiletin during the first four days of the study. Cisplatin (4 mg/kg, i.p. twice a day) was administered to the experimental groups on the 5th day of the study. All rats were sacrificed on the 10th day of the study. BDNF, NGF, G6PD, GPx, tGSH and MDA levels were determined in brain. In addition, routin histolopathological analysis and caspase-3 immunoreactivity assay were conducted. RESULTS: BDNF concentrations increased in nobiletin-administered groups, compared to Control and CIS and that the increase was statistically significant in NOB + CIS (p < 0.05). It was also found that G6PD activity increased (p < 0.05) in the nobiletin-administered groups, compared to control and CIS. Histopathologically, neuronal degeneration, oedema and gliosis increased in CIS compared to Control, and nobiletin administration decreased neuronal degeneration and oedema compared to CIS (p < 0.05). Cisplatin increased (p < 0.05) caspase-3 immunoreactivity in cerebrovascular endothelium and neurons compared to Control, while nobiletin administration decreased caspase-3 immunoreactivity in cerebrovascular endothelium. Caspase-3 immunoreactivity in neurons decreased only in NOB + CIS (p < 0.05). CONCLUSION: Nobiletin increased BDNF concentration and G6PD activity in brain and when evaluated together with histopathological and immunohistochemical findings, it may have antioxidant, antiapoptotic and neuroprotective effects against cisplatin.

Ultra-Wideband Air-to-Ground Propagation Channel Characterization in an Open Area.

This paper studies the air-to-ground ultra-wideband channel through propagation measurements between 3.1 GHz to 4.8 GHz using unmanned-aerial-vehicles (UAVs). Different line-of-sight (LOS) and obstructed-LOS scenarios and two antenna orientations were used in the experiments. Multipath channel statistics for different propagation scenarios were obtained, and the Saleh-Valenzuela model was found to provide a good fit for the statistical channel model. An analytical path loss model based on antenna gains in the elevation plane is provided for unobstructed UAV hovering and moving (in a circular path) propagation scenarios.

Water leakage management by district metered areas at water distribution networks.

The aim of this study is to design a district metered area (DMA) at water distribution network (WDN) for determination and reduction of water losses in the city of Malatya, Turkey. In the application area, a pilot DMA zone was built by analyzing the existing WDN, topographic map, length of pipes, number of customers, service connections, and valves. In the DMA, International Water Association standard water balance was calculated considering inflow rates and billing records. The ratio of water losses in DMAs was determined as 82%. Moreover, 3124 water meters of 2805 customers were examined while 50% of water meters were detected as faulty. This study revealed that DMA application is useful for the determination of water loss rate in WDNs and identify a cost-effective leakage reduction program.

Effect of reproductive characteristics, body mass index, and anterior/posterior vaginal compartment defects on the short-term success of abdominal sacrocolpopexy.

OBJECTIVE: Vaginal vault prolapse is caused by the loss of apical support in the cardinal-uterosacral ligament complex. Abdominal sacrocolpopexy (ASCP) is one means of repairing vaginal vault prolapse. In the present study, we investigated the effects of reproductive factors, body mass index (BMI), and anterior or posterior vaginal compartment defects on short-term outcomes of ASCP. METHOD: We retrospectively studied 70 women who had undergone ASCP between February 2012 and November 2012 in our clinic. RESULT: There were no significant differences in the complication rate among menopausal, nonmenopausal women, and grand multiparous patients. Operational success was not significantly affected by menopausal status. The long-term rate of grade ≥ 2 prolapse in the apical, anterior, or posterior vaginal wall after ASCP did not differ significantly by menopausal status. Correlation analysis showed that BMI was not associated with operational success in the early postoperative period in patients with vaginal prolapse and was not associated with the detection of grade ≥ 2 prolapse in apical, anterior, and posterior compartments after 1 year. CONCLUSION: ASCP should be the first-line treatment for obese/overweight, menopausal, or grand multiparous patients with additional anterior or posterior vaginal vault prolapse.

The effectiveness of anti-R. equi hyperimmune plasma against R. equi challenge in thoroughbred Arabian foals of mares vaccinated with R. equi vaccine.

This study aimed to determine the effectiveness of a pregnant mare immunization of a Rhodococcus equi (R. equi) vaccine candidate containing a water-based nanoparticle mineral oil adjuvanted (Montanide IMS 3012) inactive bacterin and virulence-associated protein A (VapA), as well as the administration of anti-R. equi hyperimmune (HI) plasma against R. equi challenge in the mares' foals. The efficacy of passive immunizations (colostral passive immunity by mare vaccination and artificial passive immunity by HI plasma administration) was evaluated based on clinical signs, complete blood count, blood gas analysis, serological response (ELISA), interleukin-4 (IL-4) and interferon gamma (IFN- γ ), total cell count of the bronchoalveolar lavage fluids (BALF) samples, reisolation rate of R. equi from BALF samples (CFU/mL), lung samples (CFU/gr), and lesion scores of the organs and tissue according to pathological findings after necropsy in the foals. The vaccination of pregnant mares and HI plasma administration in the foals reduced the severity of R. equi pneumonia and lesion scores of the organs and tissue by 3.54-fold compared to the control foals. This study thus indicates that immunization of pregnant mares with R. equi vaccine candidate and administration of HI plasma in mares' foals effectively protect foals against R. equi challenge.

Evaluation and normalization of a set of reliable reference genes for quantitative sgk-1 gene expression analysis in Caenorhabditis elegans-focused cancer research.

Multiple signaling pathways have been discovered to play a role in aging and longevity, including the insulin/IGF-1 signaling system, AMPK pathway, TOR signaling, JNK pathway, and germline signaling. Mammalian serum and glucocorticoid-inducible kinase 1 (sgk-1), which has been associated with various disorders including hypertension, obesity, and tumor growth, limits survival in C. elegans by reducing DAF-16/FoxO activity while suppressing FoxO3 activity in human cell culture. C. elegans provides significant protection for a number of genes associated with human cancer. The best known of these are the lin-35/pRb (mammalian ortholog pRb) and CEP-1 (mammalian ortholog p53) genes. Therefore, in this study, we aimed to investigate the expression analyzes of sgk-1, which is overexpressed in many types of mammalian cancer, in mutant lin-35 and to demonstrate the validation of reference genes in wild-type N2 and mutant lin-35 for C. elegans-focused cancer research. To develop functional genomic studies in C. elegans, we evaluated the expression stability of five candidate reference genes (act-1, ama-1, cdc-42, pmp-3, iscu-1) by quantitative real-time PCR using five algorithms (geNorm, NormFinder, Delta Ct method, BestKeeper, RefFinder) in N2 and lin-35 worms. According to our findings, act-1 and cdc-42 were effective in accurately normalizing the levels of gene expression in N2 and lin-35. act-1 and cdc-42 also displayed the most consistent expression patterns, therefore they were utilized to standardize expression level of sgk-1. Furthermore, our results clearly showed that sgk-1 was upregulated in lin-35 worms compared to N2 worms. Our results highlight the importance of definitive validation using mostly expressed reference genes.

Protective and therapeutic effects of nobiletin against cisplatin-induced nephrotoxicity in rats.

Possible protective and therapeutic effects of nobiletin on kidney in a cisplatin-induced nephrotoxicity rat model were investigated. Forty male albino rats were divided into four groups: control, cisplatin (CIS), cisplatin+nobiletin (CIS+NOB), and nobiletin+cisplatin (NOB+CIS). At the end of the study, the rats were subjected to biochemical, histological and immunohistochemical analyzes. Compared to the control group, tGSH (p < 0.05) levels, and G6PD (p < 0.05) and GPx (p < 0.001) activities, were increased in the CIS group; while significant (p < 0.05) decreases occurred in the MDA and TOC levels. Histopathologically, the kidneys of the groups administered nobiletin (CIS+NOB, NOB+CIS) were significantly different from the CIS group, being closer to control group in terms of degeneration and hyaline cylinder formation in the tubules (p < 0.05). While dilatation in the tubules, protein-rich fluid and hyaline cylinder formation in the lumen were most common in the CIS group, a significant decrease (p < 0.05) of these parameters was seen in the nobiletin groups (CIS+NOB, NOB+CIS). This study suggests that nobiletin can be effective in preventing and ameliorating toxic effects of cisplatin on the kidney.

Effect of Acticoat(®) and Cutinova Hydro(®) on wound healing.

In this study, the effects of the wound-covering materials, Acticoat(®) and Cutinova Hydro(®) , on wound healing have been studied in rabbit models with open and tissue-lost wounds with full-thickness flank excisions. Rabbits were used as subjects with three groups of four rabbits each, and trial periods of 7, 14 and 21{\uns}days. Four circular wounds, of 1.5 cm diameter were made two on the right (one of them control) and two on the left (one of them control) of the dorsal sides of the abdomen. Acticoat(®) and Cutinova Hydro(®) were applied on the wounds with suture for a period of 21 days and one each placed on the right and left sides as control with gauze. Biopsy specimens were taken from the animals at the end of the research period to check the length of the epithelium, epithelial thickness, size of wounds, wound granulation tissue formation and histopathological evaluation for clarity. The Acticoat(®) group showed better healing and scar formation compared to the Cutinova Hydro(®) group by macroscopic examination. Epithelial wound length and clarity in terms of statistical difference occurred on day 21 (P <0.05); while the length of the wound epithelium decreased patency, epithelial thickness on days~7, 14 and 21, showed no statistical differences (P >0.05). As a result, the Acticoat(®) wound dressing was determined as a more reliable for the early wound healing. This study has shown the short-term clinical benefits of hydroactive, polyurethane dressings in the management of acute wounds. However, longer periods of wound healing procedure should be planned for reliable and safe results of wound dressing. It has also been concluded that microbiological analyses should be included for more robust and reliable comparisons.

Restructuring anaerobic hydrolysis kinetics in plant-wide models for accurate prediction of biogas production.

In this study, the effect of anaerobic hydrolysis rate on biogas production was investigated with mesophilic digesters in seven large-scale wastewater treatment plants. A linear correlation was determined between the percentage of primary sludge mass in the total sludge fed to the digester and the overall anaerobic hydrolysis rate. The anaerobic hydrolysis rate of primary sludge was determined to be three times higher than that of biological sludge. The reduction factors for anaerobic hydrolysis (ηHYD,ana) were identified in the range of 0.11-0.30 which is lower compared to the recommended range (0.30-0.50) given in the literature. This study proposes a new model approach where anaerobic degradation kinetics of influent originated (XB) and decay originated (XB,E) particulate biodegradable organics are separated. Current plant-wide models with a single kinetic expression required recalibration of the model for calculating biogas flowrate for each treatment facility with different primary and secondary sludge ratios fed to the digesters. The new model structure is able to predict biogas production of all wastewater treatment plants without any recalibration effort by segregating degradation kinetics of two particulate biodegradable organic fractions (XB, XB,E).

Burnout in primary healthcare physicians and nurses in Turkey during COVID-19 pandemic.

BACKGROUND: Due to additional responsibilities and uncertainties during the COVID-19 pandemic, primary healthcare (PHC) workers are at increased risk of burnout. AIM: To determine and compare the burnout levels and related factors in PHC nurses and family physicians (FPs) during the COVID-19 pandemic. METHODS: An online survey was delivered to PHC workers. Non-random sampling method was used. To evaluate burnout, the Maslach Burnout Inventory was used, which investigates burnout in three categories: emotional exhaustion (EE), depersonalization (DP) and reduced personal accomplishment (PA). Multivariate linear regression was used to analyze factors associated with burnout for FPs and nurses separately. FINDINGS: Among the participants, 55.7% were nurses, the mean age was 42.34. FPs and nurses experienced similar levels of burnout in terms of EE. Family physicians had higher levels of low PA and DP. Based on the results of the multivariate analysis, while higher EE levels were significantly associated with unequal distribution of workload and communication problems within the Family Health Center for physicians, the unequal distribution of PPE, lack of appreciation by patients or colleagues and restrictions on work-related rights were relevant factors for nurses. Lack of appreciation and restrictions of the rights were associated with increased DP scores in both groups. Unequal distribution of workload was also associated with reduced PA among FPs. CONCLUSION: PHC physicians and nurses are affected by burnout in different ways under the conditions of the COVID-19 pandemic based on gender, socioeconomic status and working conditions. To protect the mental health of PHC workers in the next public health emergency, clarification in the organization of services, empowering PHC workers in emergency risk communication and provision of timely, adequate and free PPE is essential. It is also crucial to ensure the rights of health workers through macro policy changes especially during emergencies.

Family planning choices in couples using contraception without knowing they are infertile: should newly-wed men undergo a routine spermiogram?

INTRODUCTION: Newly-weds choose to use contraception either to spend the first years of their marriage more freely, because of economic reasons or because of the increase in working career women. We studied the reasons for infertility and the rate of contraception use in the first years of marriage among couples with primary infertility and evaluated the use of a spermiogram as a screening test in newly-wed men. SUBJECTS AND METHODS: In this cross-sectional study, 302 couples with primary infertility who were treated at our infertility clinic were included in the study. The couples were divided into 2 groups: group 1 (infertile couples who have used contraception) consisted of 67 couples and group 2 (infertile couples who did not use contraception) consisted of 235 couples. RESULTS: Sixty-seven (22.5%) infertile couples stated that they had used no contraception in the first years of their marriage. In group 1, 35.8% of couples were diagnosed as having unexplained infertility, while 28.4% of them had male factor, 31.3% female factor and 4.5% a combination of male and female factor infertility. Sixteen men with male factor infertility used coitus interruptus (3-36 months) or condoms (6-12 months) unnecessarily. CONCLUSIONS: Infertility counseling in the early days of marriage and a spermiogram performed at that time could be beneficial for the newly-wed couples even if they do not want a child at the time. To perform a spermiogram as a screening test in all newly-wed men should be discussed.

Characterization and assessment of a large-scale domestic advanced wastewater treatment plant in Turkey.

The paper presents new studies about the removal efficiencies and characterization of the Municipal Wastewater Treatment Plant (MWWTP) in Kayseri, Turkey, which is serving for 800,000 population equivalents with the capacity of 110,000 m(3)/day, between 2006 and 2009. Kayseri discharges its effluents to Karasu Creek that downstream joins the Kizilirmak river, the longest river in Turkey discharging into the Black Sea. Four years of operation data between 2006 and 2009 calendar years were obtained from KASKI General Directorate. Influent and effluent samples were collected daily and suspended solids (SS), chemical oxygen demand (COD), biochemical oxygen demand in 5 days (BOD(5)), total nitrogen (TN), and total phosphorus (TP) were measured, aiming to study the evolution of the removal efficiencies for each year. The following yearly mean removal efficiencies were performed in the treatment plant: 94%, 97%, 97%, 95% for SS; 94%, 96%, 95%, 95% for COD; 98%, 98%, 98%, 98% for BOD(5); 84%, 87%, 89%, 82% for TN; and 71%, 86%, 80%, 86% for TP, in 2006, 2007, 2008, and 2009, respectively. The performance of Kayseri MWWTP was given both in terms of influent and effluent quality and in comparison with the current legislation on discharge limits to the receiving body. During the studied period, mean concentrations in the effluent did not exceed the imposed limits, but sometimes, higher values were noticed for SS, TN, and TP. In conclusion, the plant performances concerning these parameters were excellent and Kayseri MWWTP was operating efficiently according to the conventional control parameters.

Attention mechanism and mixup data augmentation for classification of COVID-19 Computed Tomography images.

The Coronavirus disease is quickly spreading all over the world and the emergency situation is still out of control. Latest achievements of deep learning algorithms suggest the use of deep Convolutional Neural Network to implement a computer-aided diagnostic system for automatic classification of COVID-19 CT images. In this paper, we propose to employ a feature-wise attention layer in order to enhance the discriminative features obtained by convolutional networks. Moreover, the original performance of the network has been improved using the mixup data augmentation technique. This work compares the proposed attention-based model against the stacked attention networks, and traditional versus mixup data augmentation approaches. We deduced that feature-wise attention extension, while outperforming the stacked attention variants, achieves remarkable improvements over the baseline convolutional neural networks. That is, ResNet50 architecture extended with a feature-wise attention layer obtained 95.57% accuracy score, which, to best of our knowledge, fixes the state-of-the-art in the challenging COVID-CT dataset.

Dataset on social and psychological effects of COVID-19 pandemic in Turkey.

This data was gathered to investigate how individuals' levels of intolerance to distress and instant anxiety are related to some of the behaviors that people can change in response to the COVID-19 pandemic. We present a dataset based on a four-wave survey of the social and psychological effects of the COVID-19 pandemic in Turkey (N = 2,817). Turkey was heavily impacted by the first waves of infections in 2020, and citizens were forced to adapt to governmental measures. So, the dataset provides unique opportunities to investigate the COVID-19 pandemic's role in shaping people's intolerance to distress and instant anxiety. The survey considered personal cleaning behavior, bank/credit card usage, online spending habits, individual security perception, and stockpile behavior. Furthermore, in this data, whether an individual or a household member was officially diagnosed with COVID-19 and socio-demographic indicators were determined. Hence, the resulting dataset can enable various analyses on social, psychological, perceived security, and self-rated health, influencing how individuals' levels of intolerance to distress and instant anxiety.

Quantifying the economic impact of COVID-19 on the U.S. hotel industry: Examination of hotel segments and operational structures.

The COVID-19 pandemic has had substantial negative impacts on the global economy. While all sectors of the economy are expected to be adversely affected, the economic implications of this pandemic for the hotel industry have not yet been widely investigated. The purpose of this study is to examine the extent to which the COVID-19 pandemic has affected the U.S. hotel industry. The results showed that daily room OCC, ADR and RevPAR have plunged about 74%, 47% and 86%, respectively. Although the impact is observed across all hotel segments, economy-scale hotels were more resilient, whereas luxury-scale hotels experienced the largest decline. Also, chain-managed hotels are the most affected by the COVID-19 pandemic as compared to franchise and independent hotels. Quantifying the magnitude of this impact, we found that the U.S. hotel industry's revenue losses accumulated to over $30 billion between March-2020 and May-2020. Implications for practitioners, policy-makers, and researchers are discussed.