bluuebunny/crossref_metadata_2025 huggingface dataset:
Advancing fertility preservation in prepubertal mice: Efficacy of ovarian tissue culture and in vitro growth in mature oocyte development
Authors: Chen Yuekun , Wakimoto Yu , Yano Mizuho , Nakagawa Kohei , Hasegawa Akiko , Shibahara Hiroaki
Published: August 2024

Aim

This study aimed to evaluate the ovarian tissue culture and in vitro follicle growth as safer alternatives to cryopreservation for generating in vitro fertilization (IVF)‐ready mature oocytes from prepubertal mice without the risk of cancer cell contamination.

Methods

Ovaries from prepubertal B6D2F1 mice were cultured in α‐minimum essential medium supplemented with an estrogen receptor antagonist, ICI 182780. Culture duration was investigated to identify the optimal timeframe for follicle growth and oocyte maturation. Follicles were isolated mechanically or using 1 mg/mL collagenase and cultured in Matrigel matrix or polyvinylpyrrolidone. Oocyte development at metaphase II was induced by in vitro maturation, followed by IVF.

Results

The optimal culture duration was 2–4 days, and tissues cultured beyond this period showed significant follicular degeneration. ICI 182780 supplementation resulted in the recovery of 20.5 follicles per ovary compared with 9.5 follicles in non‐supplemented cultures (p < 0.05). Of the 452 isolated follicles, 237 (52.4%) showed growth, 150 (33.2%) underwent germinal vesicle breakdown, and 18 (4.0%) reached metaphase II. However, none of the metaphase II oocytes were successfully fertilized after IVF. Matrigel demonstrated a significantly higher in vitro maturation rate compared with polyvinylpyrrolidone in a comparative analysis of culture matrices (p < 0.001).

Conclusions

This study highlighted ovarian tissue culture and in vitro growth as effective strategies for producing mature oocytes from prepubertal mice. Further studies are required to overcome fertilization hurdles and understand the mechanisms that improve post‐IVF embryo viability.
The Sinophone lawyer: China's cross‐border impact on the legal profession
Authors: HSU CHING‐FANG
Published: August 2024

This article studies China's cross‐border impact on the legal profession, and develops the concept of the Sinophone lawyer to capture the inter‐jurisdictional transformation. Using Hong Kong as a case study, the article identifies a process of ‘Sinophonication’ brought about by Chinese capital; that is, lawyers and law firms have critically changed the language in which they practise. The fact that the Chinese language is multilingual and polyphonic further assigns different values to different aspects of linguistic proficiency and different levels of the legal profession. For law firm partners, the ability to speak Mandarin and Mandarin cultural literacy are now indispensable. For associates, the ability to read and write simplified Chinese is essential. A lower level of paralegals has been created, attracting native speakers from Mandarin‐speaking jurisdictions to serve as associates at a lower salary and with less career security. The article draws on qualitative interviews with solicitors, barristers, and foreign lawyers in Hong Kong, and quantitative data from Hong Kong Lawyer (1996–2016) and the annual reports of the Law Society of Hong Kong (1994–2016).
The Political Side of Social Enterprises: A Phenomenon‐Based Study of Sociocultural and Policy Advocacy
Authors: Mair Johanna , Rathert Nikolas
Published: August 2024

This study explores the often‐overlooked political dimension of social enterprises, particularly their advocacy activities aimed at influencing public policy, legislation, norms, attitudes, and behaviour. While traditional management research has focused on commercial activity and the beneficiary‐oriented aspects of social enterprises, this paper considers their upstream political activity. Using a phenomenon‐based approach, we analyse original survey data from 718 social enterprises across seven countries and six problem domains to identify factors associated with their engagement in advocacy. Our findings reveal that public spending and competition in social enterprises’ problem domains, as well as their governance choices – legal form, sources of income, and collaborations – are significantly associated with advocacy activities. We propose a new theoretical framework to understand these dynamics, positioning social enterprises as key players in markets for public purpose. This research underscores the importance of recognizing the political activities of social enterprises and offers new insights for studying hybrid organizing and organizations that address complex societal challenges. By highlighting the integral role of advocacy, our study contributes to a more comprehensive understanding of how social enterprises drive social change, not only through direct service provision but also by shaping the broader sociopolitical environment.
A Protocol to Determine Circadian Phase by At‐Home Salivary Dim Light Melatonin Onset Assessment
Authors: Murray Jade M. , Stone Julia E. , Abbott Sabra M. , Bjorvatn Bjorn , Burgess Helen J. , Cajochen Christian , Dekker Jip J. , Duffy Jeanne F. , Epstein Lawrence J. , Garbazza Corrado , Harsh John , Klerman Elizabeth B. , Lane Jacqueline M. , Lockley Steven W. , Pavlova Milena K. , Quan Stuart F. , Reid Kathryn J. , Scheer Frank A. J. L. , Sletten Tracey L. , Wright Kenneth P. , Zee Phyllis C. , Phillips Andrew J. K. , Czeisler Charles A. , Rajaratnam Shantha M. W. ,   International Association of Circadian Health Clinics
Published: August 2024

Internal circadian phase assessment is increasingly acknowledged as a critical clinical tool for the diagnosis, monitoring, and treatment of circadian rhythm sleep−wake disorders and for investigating circadian timing in other medical disorders. The widespread use of in‐laboratory circadian phase assessments in routine practice has been limited, most likely because circadian phase assessment is not required by formal diagnostic nosologies, and is not generally covered by insurance. At‐home assessment of salivary dim light melatonin onset (DLMO, a validated circadian phase marker) is an increasingly accepted approach to assess circadian phase. This approach may help meet the increased demand for assessments and has the advantages of lower cost and greater patient convenience. We reviewed the literature describing at‐home salivary DLMO assessment methods and identified factors deemed to be important to successful implementation. Here, we provide specific protocol recommendations for conducting at‐home salivary DLMO assessments to facilitate a standardized approach for clinical and research purposes. Key factors include control of lighting, sampling rate, and timing, and measures of patient compliance. We include findings from implementation of an optimization algorithm to determine the most efficient number and timing of samples in patients with Delayed Sleep−Wake Phase Disorder. We also provide recommendations for assay methods and interpretation. Providing definitive criteria for each factor, along with detailed instructions for protocol implementation, will enable more widespread adoption of at‐home circadian phase assessments as a standardized clinical diagnostic, monitoring, and treatment tool.
Prevalence of sleep disturbances among intensive care nurses: A systematic review and meta‐analysis
Authors: Gong Fengxiang , Mei YuChen , He Yuting , Tang Chao
Published: August 2024

Background

Demanding intensive care unit (ICU) work environments may lead to sleep disturbances in nurses, impacting their health and potentially patient safety. Yet, the prevalence remains unclear around the world.

Aims

To quantify the prevalence of sleep disturbances in intensive care nurses.

Study Design

Systematic review and meta‐analysis. A database search was conducted in Embase, PubMed, Web of Science, Scopus and CINAHL from their inception to April 2024 for relevant studies. Data from observational studies (cross‐sectional or cohort) that reported the prevalence of sleep disturbances, assessed using the Pittsburgh Sleep Quality Index (PSQI > 5), pooled in random‐effects meta‐analyses. Subgroup analyses were used to investigate variations in the prevalence estimates in terms of available variables. A Preferred Reporting Items for Systematic Reviews and Meta‐analyses (PRISMA)‐compliant protocol was registered in PROSPERO (CRD42023476428).

Results

In total, 24 articles were included in this study published from 1996 to 2023. Included studies were from 15 unique countries. Almost all of the studies were descriptive cross‐sectional studies (n = 22; 91.7%). The included studies encompassed a range of intensive care nurses, from 42 to 605, involving a total of 3499 intensive care nurses. The reported proportion of intensive care nurses with sleep disturbances ranged from 20.0% to 100.0%, with a median of 76.7% (interquartile range: 62.9–85.7). The pooled prevalence of sleep disturbances in intensive care nurses was 75.1% (95% confidence interval: 37.2–53.1; 95% prediction interval: 30.5–95.4).

Conclusions

Sleep disturbance is a common issue in intensive care nurses. The study results highlight the importance of implementing effective interventions as early as possible to improve ICU sleep quality.

Relevance to Clinical Practice

High prevalence of sleep disturbances among intensive care nurses necessitates global interventions. Gender‐neutral approaches that acknowledge comparable risks and stable prevalence over time require long‐term strategies. Raising awareness through programmes is vital for implementing evidence‐based interventions to promote sleep health in intensive care nurses.
Acute care of cyclic vomiting syndrome and cannabinoid hyperemesis syndrome in the home and emergency department for: Special supplement/proceedings of 3rd international symposium
Authors: Levinthal David J. , Killian Blynda , Issenman Robert M.
Published: August 2024

Background

Cyclic vomiting syndrome (CVS) and cannabinoid hyperemesis syndrome (CHS) are both characterized by episodic, acute transitions from asymptomatic states to highly symptomatic states of nausea, repetitive vomiting, and often severe abdominal pain. Patients with CVS and CHS face significant challenges to abort or mitigate episodes at home and often require emergency department (ED)‐based care.

Purpose

This paper reviews the current treatment approach to abort acute CVS and CHS episodes at home and in ED settings. Multiple pharmacologic and nonpharmacologic interventions have been demonstrated to potentially abort CVS or CHS episodes. Systemic pharmacologic agents often used as abortive therapy include triptans, antiemetics, anxiolytics, NK‐1 receptor antagonists, antipsychotics, sedatives in general, and various analgesic / anti‐inflammatory medications. Nonsystemic, nonpharmacologic approaches include reducing external stimuli (quiet room, dim lights, etc.), and hot water bathing or the application of topical capsaicin cream. More research is needed to develop evidence‐based, individualized abortive treatment plans, as well as to determine whether the abortive treatment for CVS requires a fundamentally different approach than for CHS. When home‐based approaches fail, all patients with CVS or CHS should receive nonjudgmental, informed, and compassionate care in the ED to abort their episode. Patients with more severe forms of CVS/CHS who require more frequent ED utilization should develop care plans with their ED to assure predictable and effective treatment.
Pleomorphic adenoma and carcinoma ex‐pleomorphic adenoma tumorigenesis: A proteomic analysis
Authors: Zanella Virgílio Gonzales , Costa Sara Ferreira Dos Santos , Schuch Lauren Frenzel , Pilar Emily Ferreira Salles , Paes Leme Adriana Franco , dos Santos Jean Nunes , Khurram Syed Ali , Elalawy Fatima , Bingle Lynne , Nunes Fabio Daumas , Fonseca Felipe Paiva , Vargas Pablo Agustin , Martins Manoela Domingues , Wagner Vivian Petersen
Published: August 2024

Objectives

To conduct a comprehensive proteomic analysis of normal salivary gland tissue, pleomorphic adenoma (PA), and carcinoma ex‐pleomorphic adenoma (CXPA), and validate the proteomic findings using immunohistochemistry.

Methods

Six normal salivary gland tissues, seven PA and seven CXPA samples underwent laser microdissection followed by liquid chromatography coupled to mass spectrometry. Protein identification and quantification were performed using MaxQuant software. Statistical analysis and functional enrichment were conducted using the Perseus platform and STRING tool, respectively. Immunohistochemistry was used for validation.

Results

Comparative proteomic analysis revealed 2680 proteins across the three tissue types, with 799 significantly altered between groups. Translocation protein SEC63 homolog, Annexin A6 and Biglycan were up‐regulated in CXPA compared to PA. Decorin was markedly up‐regulated in both PA and CXPA compared to normal salivary gland (log2 fold changes of 7.58 and 7.38, respectively). Validation confirmed elevated levels of Biglycan and Decorin in the extracellular matrix of CXPA compared to PA.

Conclusions

Proteomic analysis identified differential protein expression patterns associated with malignant transformation of PA into CXPA. Findings indicate a crucial role for extracellular matrix proteins, specifically Biglycan and Decorin, in the tumorigenic progression of PA and CXPA.
Current Status and Outcomes of Living Donor Liver Transplantation for Pediatric Acute Liver Failure: Results From a Multicenter Retrospective Study Over Two Decades
Authors: Uchida Hajime , Hong Suk Kyun , Okumura Shinya , Cherukuru Ramkiran , Sanada Yukihiro , Yamada Yohei , Reddy Mettu Srinivas , Matsuura Toshiharu , Hara Takanobu , Chen Chao‐Long , Yi Nam‐Joon , Ikegami Toru , Kasahara Mureo ,   The iLDLT Vanguard Multi‐center Study Committee
Published: August 2024

Background

Although the outcomes of living donor liver transplantation (LDLT) for pediatric acute liver failure (PALF) have improved, patient survival remains lower than in patients with chronic liver disease. We investigated whether the poor outcomes of LDLT for PALF persisted in the contemporary transplant era.

Methods

We analyzed 193 patients who underwent LDLT between December 2000 and December 2020. The outcomes of patients managed in 2000–2010 (era 1) and 2011–2020 (era 2) were compared.

Results

The median age at the time of LDLT was 1.2 years both eras. An unknown etiology was the major cause in both groups. Patients in era 1 were more likely to have surgical complications, including hepatic artery and biliary complications (p = 0.001 and p = 0.013, respectively). The era had no impact on the infection rate after LDLT (cytomegalovirus, Epstein–Barr virus, and sepsis). The mortality rates of patients and grafts in era one were significantly higher (p = 0.03 and p = 0.047, respectively). The 1‐ and 5‐year survival rates were 76.4% and 70.9%, respectively, in era 1, while they were 88.3% and 81.9% in era 2 (p = 0.042). Rejection was the most common cause of graft loss in both groups. In the multivariate analysis, sepsis during the 30 days after LDLT was independently associated with graft loss (p = 0.002).

Conclusions

The survival of patients with PALF has improved in the contemporary transplant era. The early detection and proper management of rejection in patients, while being cautious of sepsis, should be recommended to improve outcomes further.
Comparison of Long‐Term Outcomes Achieved With Live Donor and Split Deceased Donor Liver Grafts in Pediatric Liver Transplantation
Authors: Barbier Louise , Hitchins Charlotte , Carr‐Boyd Peter , Evans Helen M. , McCall John
Published: August 2024

Background

The aim of the present study was to compare the outcomes of pediatric LT with left liver grafts, obtained either from a living donor (LD) or a split deceased donor (sDD).

Methods

Retrospective single‐center study from 2002 to 2022. All pediatric LT with left liver grafts (not including middle hepatic vein) from LD or sDD were included. Reduced grafts were not included.

Results

A total of 112 pediatric LT were performed: 58 with LD grafts and 54 with sDD grafts (17 split ex situ and 37 in situ). Donor characteristics were similar, apart from donor age (33 years in LD vs. 30 years in sDD, p = 0.03). Indications were similar with 55% biliary atresia in each group. Retransplantation was more frequently performed in the sDD group (2% vs. 15%, p = 0.01). Recipient age, weight, and PELD score at transplant were not significantly different between groups. Cold ischemia time was longer for sDD (158 min in LD vs. 390 min in sDD; p < 0.0001). Posttransplant peak ALT was higher with sDD grafts (1470 vs. 1063, p = 0.018), and hospital stay was longer with sDD grafts (27 vs. 21 days, p = 0.005). However, there was no difference between groups in terms of major morbidity (Dindo‐Clavien grade ≥3), vascular and biliary complications, and 90‐day mortality. Patient survival at 10 years was 93.1% for LD and 92.8% for sDD (p = 0.807). Graft survival at 10 years was 89.7% for LD and 83.1% for sDD (p = 0.813).

Conclusions

Technically similar LD and sDD grafts achieve very similar postoperative and long‐term outcomes with excellent patient and graft survival.
Pharmacological Treatment for Dialysis‐Related Muscle Cramps: A Systematic Review
Authors: Mantilla‐Manosalva Nidia , Guadarrama Santiago , Bedoya‐Muñoz Lennis Jazmin , Giraldo‐Moreno Sara , Cuellar‐Valencia Laura , Iriarte‐Aristizábal María Fernanda , León Marta Ximena , Mendoza‐Montenegro Fernan Alejandro , Correa‐Morales Juan Esteban
Published: August 2024

Background

Patients with end‐stage renal disease undergoing dialysis suffer from muscle cramps, a prevalent and burdensome symptom for which there is a paucity of efficient and safe treatments.

Aim

What is the efficacy and safety of pharmacological interventions for the treatment of dialysis‐related muscle cramps?

Design

A systematic review was conducted in OVID, CINAHL, PubMed, Web of Science, and Central Cochrane databases up to August 25, 2023.

Data Sources

Experimental studies reporting on a pharmacological intervention for the treatment of dialysis‐related muscle cramps were included. The review followed the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis, and the studies quality was assessed with the RoB2 tool.

Results

A total of 4660 studies were retrieved, and 13 articles were included. The studies reported on nine interventions: vitamin C, vitamin E, vitamin K2, vitamin B7, dextrose solutions, gabapentin, sodium chloride, creatine monohydrate, and L‐carnitine. The studies testing L‐carnitine and creatine monohydrate were the only ones deemed to have a low risk of bias. Side effects were reported in only two trials, consisting primarily of gastrointestinal discomfort and hyperglycemia. Vitamins C and E are the two most studied interventions that showed positive results in reducing the frequency, severity, and duration of dialysis‐related muscle cramps. L‐carnitine is a promising intervention that warrants further investigation.

Conclusion

Our review consolidates the existing evidence, elucidating the range of treatments along with their potential benefits and limitations. Future studies should uphold high‐quality standards, incorporate patient‐reported outcomes, and utilize well‐defined, robust samples to improve patient care.
Specific antibody responses to Qβ‐displayed Plasmodium falciparum‐derived UB05 and MSP3 proteins in mother–neonate couples
Authors: Lissom Abel , Megnekou Rosette , Tchouangueu Thibau Flaurant , Ngu Loveline , Djontu Jean Claude , Ouambo Herve Fotso , Sanders Carrie , Tchadji Jules Colince , Sake Carole Stephanie , Tchuandom Salomon Bonsi , Bawage Swapnil , Okoli Arinze Stanley , Park Chae Gyu , Waffo Alain Bopda , Godwin Nchinda Wapimewah
Published: August 2024

Malaria blood‐stage parasite is a critical pathogenic stage responsible for serious adverse outcomes in pregnant women and their neonates. Immunoglobulin G (IgG) antibody responses specific to various asexual blood‐stage antigens were well reported in non‐pregnant individuals. However, little is still known during placental malaria. To assess the antibody responses specific to Plasmodium falciparum‐derived MSP3 and UB05 malaria vaccine candidates in mother‐neonate couples, mother's peripheral blood and neonate's cord blood samples were collected at delivery. After malaria diagnostic, plasma levels of IgG and IgG subclass responses specific to UB05, MSP3 and UB05‐MSP3 were determined using ELISA. As outcomes, both mothers and neonates had significantly higher IgG responses to UB05 and UB05‐MSP3 compared to anti‐MSP3 IgG (p < 0.05), irrespective of malaria status. Significant negative correlations were observed between IgG levels specific to the three antigens and parasitaemia (p < 0.01). Anti‐UB05 and anti‐UB05‐MSP3 IgG levels in neonates showed a significant positive correlation with the corresponding mothers' antibodies (rs = 0.25 with p = 0.04; rs = 0.31 with p = 0.01, respectively). UB05MSP3‐specific IgG3 and IgG1 subclass responses were significantly higher than the IgG4 subclass (p < 0.01). The neonates IgG1 and IgG3 levels positively correlated with the corresponding antibody subclasses of mothers. These findings suggest an association between UB05 and UB05‐MSP3‐specific antibody responses and malaria control during pregnancy. Maternal–foetal transfer of MSP3 and UB05‐specific IgG occurs during pregnancy, suggesting the interest in the future malaria vaccination strategies in pregnant women to generate early protective immunity in baby against malaria.
Saccade Latency and Metrics in the Interleaved Pro‐ and Anti‐Saccade Task in Open Skill Sports Athletes
Authors: Chen Jui‐Tai , Kan Nai‐Wen , Barquero Cesar , Teo Moeka Mong Jia , Wang Chin‐An
Published: August 2024

Evidence has demonstrated that athletes exhibit superior cognitive performance associated with executive control. In the oculomotor system, this function has been examined using the interleaved pro‐saccade and anti‐saccade task (IPAST), wherein participants, prior to target appearance, are instructed to either automatically look at the peripheral target (pro‐saccade) or suppress the automatic response and voluntarily look in the opposite direction (anti‐saccade). While the IPAST has provided much insight into sensorimotor and inhibitory processing, it has yet to be performed in athletes. Moreover, limited research has examined saccade metrics in athletes. Here, we examined saccade latency and movement kinematics in the IPAST among athletes (N = 40) and nonathletes (NON) (N = 40). Higher direction error rates were obtained in the anti‐saccade compared to the pro‐saccade condition, with no differences between athletes and NON noted. Significantly faster saccade latencies were observed in athletes compared to NON in both conditions, in addition to faster pro‐saccades compared to anti‐saccades. Furthermore, athletes showed significantly higher frequencies and faster latencies of express saccades compared to NON in correct pro‐saccades. Additionally, athletes exhibited significantly faster latencies of express saccades compared to NON in erroneous anti‐saccades. Differences in saccade metrics between athletes and NON were not seen. Overall, these findings demonstrate that athletes display altered saccade performance likely associated with sensorimotor and preparatory processing, highlighting the potential of using IPAST to objectively investigate sensorimotor and cognitive functions in athletes.
Voluntary co‐contraction of ankle muscles alters motor unit discharge characteristics and reduces estimates of persistent inward currents
Authors: Gomes Matheus M. , Jenz Sophia T. , Beauchamp James A. , Negro Francesco , Heckman C. J. , Pearcey Gregory E. P.
Published: August 2024

Motoneuronal persistent inward currents (PICs) are facilitated by neuromodulatory inputs but are highly sensitive to local inhibitory circuits. Estimates of PICs are reduced by group Ia reciprocal inhibition, and increased with the diffuse actions of neuromodulators released during remote muscle contraction. However, it remains unknown how motoneurons function in the presence of simultaneous excitatory and inhibitory commands. To probe this topic, we investigated motor unit discharge patterns and estimated PICs during voluntary co‐contraction of ankle muscles, which simultaneously demands the contraction of agonist–antagonist pairs. Twenty participants performed triangular ramps of both co‐contraction (simultaneous dorsiflexion and plantar flexion) and isometric dorsiflexion to a peak of 30% of their maximum muscle activity from a maximal voluntary contraction. Motor unit spike trains were decomposed from high‐density surface EMG activity recorded from tibialis anterior using blind source separation algorithms. Voluntary co‐contraction altered motor unit discharge rate characteristics. Discharge rate at recruitment and peak discharge rate were modestly reduced (∼6% change; P < 0.001; d = 0.22) and increased (∼2% change; P = 0.001, d = −0.19), respectively, in the entire dataset but no changes were observed when motor units were tracked across conditions. The largest effects during co‐contraction were that estimates of PICs (ΔF) were reduced by ∼20% (4.47 vs. 5.57 pulses per second during isometric dorsiflexion; P < 0.001, d = 0.641). These findings suggest that, during voluntary co‐contraction, the inhibitory input from the antagonist muscle overcomes the additional excitatory and neuromodulatory drive that may occur due to the co‐contraction of the antagonist muscle, which constrains PIC behaviour.

image

Key points

Voluntary co‐contraction is a unique motor behaviour that concurrently provides excitatory and inhibitory synaptic input to motoneurons.

Co‐contraction of agonist–antagonist pairs alters agonist motor unit discharge characteristics, consistent with reductions in persistent inward current magnitude.
An Optimized and Reduced Chemical Kinetic Model for Hydrogen and Natural Gas Blends Combustion in Industrial Gas Turbines
Authors: Rahman Ramees K. , Kancherla Raghu , Vogel Gregory , Vasu Subith S.
Published: August 2024

Natural gas is one of the common fuels that is used in gas turbines for power generation. Due to its interest in power generation and other applications, there are several chemical kinetic models available in the literature for natural gas. The power generation sector is moving toward decarbonization and there has been increased interest in replacing conventional fuels with fuels that produce less/zero carbon emissions like hydrogen. Pure hydrogen has a very wide flammability range and poses risks related to flashback and high thermal NOx production. Blending hydrogen with natural gas helps in having better control over the fuel properties. However, the literature lacks well-validated chemical kinetic models for the combustion of hydrogen blended natural gas for undilute mixtures at gas turbine-relevant conditions (8–16 bar). Hence, in this work, we develop a detailed chemical kinetic model for hydrogen-blended natural gas and validate it with a wide range of experimental data for both dilute and undilute mixtures relevant to gas turbine operating conditions. We outline the strengths and weaknesses of the current mechanism to aid future users of our chemical kinetic mechanism. The detailed chemical kinetic mechanism is then reduced to two smaller versions (60 species and 44 species mechanisms) without significant loss in accuracy using Directed Relation Graph with Error Propagation (DRGEP). To improve the prediction for pure hydrogen combustion while retaining all other predictive capabilities, an optimization is carried out for the most sensitive reactions for hydrogen combustion. The resultant mechanism can predict a wide range of experimental results with the least cumulative error.
Teaching Aero-Engine Performance: From Analytics to Hands-On Exercises Using Gas Turbine Performance Software
Authors: Jeschke Peter , Koschel Wolfgang , Klumpp Christian , Weintraub Daniel
Published: August 2024

In this paper, we present an approach for teaching turbojet engine performance that combines mathematical analysis with the use of performance software to provide students with a comprehensive and in-depth understanding of engine performance and how it is affected by design parameter choices. In the first part, we present the derivation of a universally valid analytical model for turbojet engine cycle design, which is the basis of the propulsion courses at RWTH Aachen University. The analytical model allows for the calculation of specific thrust as well as thermal and propulsive efficiencies as a function of pressure ratios and burner exit temperature. These are all expressed as differentiable functions. Their mathematical extremes form a basis for examining the intricate relationships in turbojet engine design. In the second part, we move from theory to practice. We utilize the GasTurb software, computing turbojet engine cycles for a wide range of cycle design parameters. The analytically derived trends are validated and errors introduced by simplifications are assessed. Differences between the analytical approach and software-based performance simulations of real engines, like temperature-dependent gas properties and secondary air systems, are emphasized and discussed, thus providing a bridge to real-world applications. In summary, this paper describes a two-step approach to teaching turbojet engine design using analytics and performance software. Each approach alone can be used to enrich and extend existing performance courses. Combining the approaches has significant benefits, improving understanding and inspiring students to pursue further research in the field of propulsion.
A Perspective on the Process and Turbomachinery Design of Compressed Air Energy Storage Systems
Authors: Maffulli Gianfranco , Grimaldi Angelo , McGillis Andrew , Succi Lorenzo , Przybytko Przemyslaw , Maceli Nicola , Brown David , Brooke Graham , Earle Scott
Published: August 2024

The present paper will describe the Baker Hughes experience in the development of the turbomachinery equipment for Hydrostor's advanced compressed air energy storage (A-CAES) system. At the core of a compressed air energy storage (CAES) plant, there is an air compressing system, followed by an air expander used to recover the stored energy. To achieve a reliable and effective solution, the expander is obtained from the architecture of Baker Hughes steam turbines, which was adapted to match the specific process needs. The criticalities that were addressed and solved to derive the expanders from the original steam turbine are presented. Specifically, the paper describes the activities performed to optimize the inlet and exhaust sections of each segment, the development of the blades for high atmospheric volume flow, and the implications that thermal transients have on the machine reliability. The inlet and exhaust sections were arranged according to the layout constraints, which were set to mitigate the effects of the thermal stresses and to reduce the weight to facilitate the machine transportation, while maintaining high aero-performance. As for the expander, a single-body configuration was selected to optimize capital expenditures and reduce leakage to atmosphere. A new set of blades derived from Baker Hughes's Steam Turbine stages were developed. This new stage is characterized by rotating blades with high radius ratio (HRR); therefore, an optimization strategy was adopted to include the mechanical constraints from the beginning of the design cycle and obtain a final geometry that can be used with different flow path and operating conditions. Finally, the three-dimensional full Navier Stokes Computational fluid dynamics analysis was used to assess the performance of the new stages in nominal and off-design conditions. A detailed analysis of the thermal transient of the expander parts with finite element analysis methods was performed to assess the life expectations of the equipment. The finite element analysis results are discussed in the paper to show the capability of the machine to sustain an extremely fast start up sequence. Compressor train is characterized by a multiple body configuration. A detailed optimization was performed to improve the efficiency and the availability of the selected solution. The low-pressure axial compressor discharge section has been optimized to reduce losses and a detailed study of rotor has been performed to evaluate the capability to withstand a high number of start and stop cycles.
The interacting effects of talker, contrast, and listener variability in cross-language speech perception
Authors: Hayes-Harb Rachel , Barrios Shannon
Published: August 2024

Building on previous observations of variability in speech research, we examine variability in speech perception study materials associated with the specific talker and contrast under examination. English-speaking listeners completed a web-based auditory AXB task involving Hindi dental-retroflex stop contrasts produced by four talkers. Main effects of talker and contrast, as well as the interaction of the two, were observed. Further, there was a great deal of individual listener variation. These findings complicate our ability to characterize the difficulty that Hindi dental-retroflex contrasts pose for English speakers, and lead to critical questions concerning the generalizability of speech perception study findings.
Vision Is Not Required to Elicit Balance Improvements From Beam Walking Practice
Authors: Richer Natalie , Peterson Steven M. , Ferris Daniel P.
Published: August 2024

Background: Beam walking is a highly studied assessment of walking balance. Recent research has demonstrated that brief intermittent visual rotations and occlusions can increase the efficacy of beam walking practice on subsequent beam walking without visual perturbations. We sought to examine the influence of full vision removal during practice walking on a treadmill-mounted balance beam. Although visual disruptions improved performance of this task, we hypothesized that removing visual feedback completely would lead to less balance improvements than with normal vision due to the specificity of practice. Methods: Twenty healthy young adults trained to walk at a fixed speed on a treadmill-mounted balance beam for 30 min, either with, or without, normal vision. We compared their balance pre-, during, and posttraining by calculating their step-offs per minute and the percentage change in step-offs per minute. Results: Balance improved in both groups after training, with no significant difference in percentage change in step-offs between the normal vision and the no vision participants. On average, the no vision participants had twice as many step-offs per minute as the normal vision group during training. Conclusion: Although previous experiments show that intermittent visual perturbations led to large enhancements of the effectiveness of beam walking training, completely removing visual feedback did not alter training effectiveness compared with normal vision training. It is likely a result of sensory reweighting in the absence of vision, where a greater weight was placed on proprioceptive, cutaneous, and vestibular inputs.
Metabolic pathway engineering of high-salinity-induced overproduction of L-proline improves high-salinity stress tolerance of an ectoine-deficient
Halomonas elongata
Authors: Khanh Huynh Cong , Kaothien-Nakayama Pulla , Zou Ziyan , Nakayama Hideki
Published: August 2024

Halophilic bacteria have adapted to survive in high-salinity environments by accumulating amino acids and their derivatives as organic osmolytes. L-Proline (Pro) is one such osmolyte that is also being used as a feed stimulant in the aquaculture industry.
Halomonas elongata
OUT30018 is a moderately halophilic bacterium that accumulates ectoine (Ect), but not Pro, as an osmolyte. Due to its ability to utilize diverse biomass-derived carbon and nitrogen sources for growth,
H. elongata
OUT30018 is used in this work to create a strain that overproduces Pro, which could be used as a sustainable Pro-rich feed additive. To achieve this, we replaced the coding region of
H. elongata
OUT30018’s Ect biosynthetic operon with the artificial self-cloned

proB
m1
AC

gene cluster that encodes the Pro biosynthetic enzymes: feedback-inhibition insensitive mutant γ-glutamate kinase (γ-GK
D118N/D119N
), γ-glutamyl phosphate reductase, and pyrroline-5-carboxylate reductase. Additionally, the
putA
gene, which encodes the key enzyme of Pro catabolism, was deleted from the genome to generate
H. elongata
HN6. While the Ect-deficient
H. elongata
KA1 could not grow in minimal media containing more than 4% NaCl,
H. elongata
HN6 thrived in the medium containing 8% NaCl by accumulating Pro in the cell instead of Ect, reaching a concentration of 353.1 ± 40.5 µmol/g cell fresh weight, comparable to the Ect accumulated in
H. elongata
OUT30018 in response to salt stress. With its genetic background,
H. elongata
HN6 has the potential to be developed into a Pro-rich cell factory for upcycling biomass waste into single-cell feed additives, contributing to a more sustainable aquaculture industry.

IMPORTANCE

We report here the evidence for
de novo
biosynthesis of Pro to be used as a major osmolyte in an ectoine-deficient
Halomonas elongata
. Remarkably, the concentration of Pro accumulated in
H. elongata
HN6 (

∆ectABC::mCherry-proB
m1
AC ∆putA

) is comparable to that of ectoine accumulated in
H. elongata
OUT30018 in response to high-salinity stress. We also found that among the two γ-glutamate kinase mutants (γ-GK
D118N/D119N
and γ-GK
D154A/E155A
) designed to resemble the two known
Escherichia coli
feedback-inhibition insensitive γ-GK
D107N
and γ-GK
E143A
, the γ-GK
D118N/D119N
mutant is the only one that became insensitive to feedback inhibition by Pro in
H. elongata
. As Pro is one of the essential feed additives for the poultry and aquaculture industries, the genetic makeup of the engineered
H. elongata
HN6 would allow for the sustainable upcycling of high-salinity waste biomass into a Pro-rich single-cell eco-feed.
Mouse hepatitis virus JHMV I protein is required for maximal virulence
Authors: Lowery Shea A. , Schuster Noah , Wong Lok-Yin Roy , Carrillo Thomas , Peters Erin , Odle Abby , Sariol Alan , Cesarz Isabella , Li Pengfei , Perlman Stanley
Published: August 2024

Betacoronaviruses
encode a conserved accessory gene within the +1 open reading frame (ORF) of nucleocapsid called the internal N gene. This gene is referred to as “I” for mouse hepatitis virus (MHV), ORF9b for severe acute respiratory CoV (SARS-CoV) and SARS-CoV-2, and ORF8b for Middle East respiratory syndrome CoV (MERS-CoV). Previous studies have shown ORF8b and ORF9b have immunoevasive properties, while the only known information for MHV I is its localization within the virion of the hepatotropic/neurotropic A59 strain of MHV. Whether MHV I is an innate immune antagonist or has other functions has not been evaluated. In this report, we show that the I protein of the neurotropic JHM strain of MHV (JHMV) lacks a N terminal domain present in other MHV strains, has immunoevasive properties, and is a component of the virion. Genetic deletion of JHMV I (rJHMV
IΔ57-137
) resulted in a highly attenuated virus both
in vitro
and
in vivo
that displayed a post RNA replication/transcription defect that ultimately resulted in fewer infectious virions packaged compared with wild-type virus. This phenotype was only seen for rJHMV
IΔ57-137
, suggesting the structural changes predicted for A59 I altered its function, as genetic deletion of A59 I did not change viral replication or pathogenicity. Together, these data show that JHMV I both acts as a mild innate immune antagonist and aids in viral assembly and infectious virus production, and suggest that the internal N proteins from different betacoronaviruses have both common and virus strain-specific properties.

IMPORTANCE

CoV accessory genes are largely studied in overexpression assays and have been identified as innate immune antagonists. However, functions identified after overexpression are often not confirmed in the infected animal host. Furthermore, some accessory proteins are components of the CoV virion, but their role in viral replication and release remains unclear. Here, we utilized reverse genetics to abrogate expression of a conserved CoV accessory gene, the internal N (“I”) gene, of the neurotropic JHMV strain of MHV and found that loss of the I gene resulted in a post replication defect that reduced virion assembly and ultimately infectious virus production, while also increasing some inflammatory molecule expression. Thus, the JHMV I protein has roles in virion assembly that were previously underappreciated and in immunoevasion.
Protein-coding circular RNA enhances antiviral immunity via JAK/STAT pathway in
Drosophila
Authors: Guo Dongyang , Xu Wen , Cui Ting , Rong Qiqi , Wu Qingfa
Published: August 2024

RNA interference (RNAi) drives powerful antiviral immunity in plants and animals so that many viruses must express viral suppressor of RNAi (VSR) to establish virulent infection. However, little is known about the immune responses conferring resistance against viruses that have evolved the counter-defensive strategy to suppress antiviral RNAi. In this study, we discover that
Drosophila
cells infected with
Drosophila
C virus (DCV), a natural viral pathogen of
Drosophila
known to harbor a potent VSR, exhibit heightened expression of circular RNA circZfh1. circZfh1 confers virus resistance in the presence of viral suppression of antiviral RNAi. Furthermore, we validate that circZfh1 encodes a 274-amino acid protein, CRAV, essential for its antiviral activity. Notably, CRAV differs from its parental Zfh1 gene in a different reading frame, with the C-terminal 69 amino acids unique to CRAV. Our analysis also reveals the presence of CRAV in species within the melanogaster subgroup, with the C-terminal unique fragment undergoing accelerated evolution. Expression of CRAV upregulates the expression of the cytokine Upd3, which binds to its receptor, stimulating the JAK-STAT pathway and enhancing the immune response to DCV infection. Notably, CRISPR/Cas9 knockout of circZfh1 significantly enhances DCV replication
in vitro
and
in vivo
, with circZfh1-knockout adult flies displaying heightened disease susceptibility to DCV. In summary, our findings unveil a
Drosophila
protein-coding circular RNA that activates an innate immune signaling pathway crucial for virus resistance following the suppression of antiviral RNAi by viruses, thereby elucidating a novel counter-defensive strategy.

IMPORTANCE

Eukaryotic hosts possess a complex, multilayered immune system that guards against pathogen invasion. In fruit flies, RNA interference (RNAi) drives robust antiviral immunity, prompting many viruses to express viral suppressors of RNAi (VSRs) to establish virulent infections. However, little is known about immune responses that confer resistance against viruses with potent VSRs. In this study, we discovered that
Drosophila
cells infected with
Drosophila
C virus (DCV), a natural viral pathogen possessing a potent VSR, upregulated the expression of circular RNA circZfh1. circZfh1 exhibits DCV-specific antiviral activity, encoding a 274-amino acid protein, CRAV, crucial for its antiviral effects. As a different reading frame from its parental Zfh1 gene, the C-terminal 69 amino acids are unique to CRAV, undergoing faster evolution. CRAV activates the JAK-STAT pathway, enhancing the immune response to DCV infection. Therefore, our work uncovers a new strategy for suppressing viral counter-defense through protein-coding circular RNA in fruit flies.
Microbiology of human spaceflight: microbial responses to mechanical forces that impact health and habitat sustainability
Authors: Nickerson Cheryl A. , McLean Robert J. C. , Barrila Jennifer , Yang Jiseon , Thornhill Starla G. , Banken Laura L. , Porterfield D. Marshall , Poste George , Pellis Neal R. , Ott C. Mark
Published: August 2024

Understanding the dynamic adaptive plasticity of microorganisms has been advanced by studying their responses to extreme environments. Spaceflight research platforms provide a unique opportunity to study microbial characteristics in new extreme adaptational modes, including sustained exposure to reduced forces of gravity and associated low fluid shear force conditions. Under these conditions, unexpected microbial responses occur, including alterations in virulence, antibiotic and stress resistance, biofilm formation, metabolism, motility, and gene expression, which are not observed using conventional experimental approaches. Here, we review biological and physical mechanisms that regulate microbial responses to spaceflight and spaceflight analog environments from both the microbe and host-microbe perspective that are relevant to human health and habitat sustainability. We highlight instrumentation and technology used in spaceflight microbiology experiments, their limitations, and advances necessary to enable next-generation research. As spaceflight experiments are relatively rare, we discuss ground-based analogs that mimic aspects of microbial responses to reduced gravity in spaceflight, including those that reduce mechanical forces of fluid flow over cell surfaces which also simulate conditions encountered by microorganisms during their terrestrial lifecycles. As spaceflight mission durations increase with traditional astronauts and commercial space programs send civilian crews with underlying health conditions, microorganisms will continue to play increasingly critical roles in health and habitat sustainability, thus defining a new dimension of occupational health. The ability of microorganisms to adapt, survive, and evolve in the spaceflight environment is important for future human space endeavors and provides opportunities for innovative biological and technological advances to benefit life on Earth.
Retrieval of refluxed Onyx cast during a paediatric AVM embolisation
Authors: Kishore Kislay , van Adel Brian
Published: August 2024

Endovascular embolisation of arteriovenous malformations (AVM) has been greatly facilitated by liquid embolic agents. While advancements in catheter technology and techniques of creating a proximal plug minimise the risk of inadvertent proximal reflux of the embolysate, this remains one of the main complications associated with use of liquid embolics.

We report a case of paediatric AVM embolisation which was complicated by parent vessel occlusion due to inadvertent proximal reflux of the embolysate in pericallosal artery. This was safely and effectively rescued using a stent retriever manoeuvre, following similar principles and tenets as in endovascular thrombectomy in stroke. This is the first case report of using a newer smaller 3 mm stentriever in a paediatric medium vessel occlusion, although for a different aetiology but with the same goal.

Bail-out or rescue strategy as presented here is an important addition to neurointerventionalists’ armamentarium to salvage a non-targeted migration of liquid embolic agent.
Extraconal orbital craniopharyngioma
Authors: Koyya Soundarya Samskruthi , Gupta Rakesh Kumar , Sharma Anil , Pati Saroj
Published: August 2024

A female, in her 60s, presented with pain and swelling of the right eye for 3 years. The radiological work-up revealed an extraconal solid-cystic orbital tumour suggestive of an epidermoid cyst. The patient underwent supraorbital craniotomy with a gross total excision of the tumour. An intraoperative diagnosis was sought, which on both squash smear and frozen section showed features of craniopharyngioma (CP), later confirmed on paraffin sections and immunohistochemistry. The orbit is a very rare site for ectopic CP, with only two cases reported in the literature. Many theories have been proposed to explain the occurrence of CP at ectopic sites. This report aims to provide insight into the different hypotheses of the pathogenesis of ectopic CP through a review of the literature.