bluuebunny/crossref_metadata_2025 huggingface dataset:
CD24 blockade promotes anti‐tumor immunity in oral squamous cell carcinoma
Authors: Zou Ke‐Long , Lan Zhou , Cui Hao , Zhao Yu‐Yue , Wang Wei‐Ming , Yu Guang‐Tao
Published: September 2022

Objectives

Our study elucidates the prognostic role of cluster of differentiation (CD) 24 expression in oral squamous cell carcinoma (OSCC) and determines whether targeting CD24 enhances the anti‐tumor immune response by inhibiting tumor‐associated macrophages (TAMs).

Materials and Methods

The expression of CD24 and CD68 was analyzed immunohistochemically via tissue microarrays constructed using 56 cohorts of patients with OSCC and 20 control specimens. Further, CD24 was inhibited in an allograft squamous cell carcinoma (SCC) related mouse model with CD24mAb to determine the tumor volume and weight. Changes in immune cells such as TAMs and T cells in the tumor microenvironment (TME) were analyzed by Flow cytometry. The expression of CD4, CD8, and Ki67 was analyzed via immunohistochemistry. The inhibition of CD24 was confirmed by Western blot and immunohistochemistry.

Results

CD24 was overexpressed in OSCC. High expression of CD24 indicated poor survival in patients with OSCC (p = 0.0334). CD24 expression was significantly correlated with CD68 (p = 0.0424). The inhibition of CD24 delayed tumor growth in vivo. A decrease in TAMs number and an increase in T cell number were confirmed, while the ability of tumor proliferation was impaired.

Conclusion

Targeting CD24 could enhance anti‐tumor immune response by inhibiting TAMs.
Accuracy of diagnostic aids in oral squamous cell carcinoma: A comparative study
Authors: James Jijy , Chandra Jagadish , Sequeira Joyce
Published: September 2022

Aim

To assess the accuracy of metastasis in cervical nodes using preoperative palpation method, ultrasonography with colour doppler (USG) and computed tomography (CT) in oral squamous cell carcinoma.

Methodology

Thirty‐one biopsy‐proven patients with OSCC who fulfilled the inclusion and exclusion criteria were included in the study. The nodal status of each was assessed by clinical palpation, USG and CT and compared with the post‐operative histopathological result. The results were evaluated statistically for sensitivity, specificity, positive predictive value and negative predictive value and accuracy.

Results

The accuracy of clinical palpation, USG and CT in diagnosing a node as metastatic was 70.9%, 100% and 87%, respectively, showing ultrasonography to be better than CT, followed by CT and clinical palpation.

Conclusion

The accuracy and sensitivity of USG in the detection of cervical lymph node metastases make it a potentially promising and cheap preoperative tool for staging neck node metastases.
Effectiveness of Platelet‐Rich Plasma in Anterior Cruciate Ligament Reconstruction: A Systematic Review of Randomized Controlled Trials
Authors: Cao Yi , Wan Ye‐da
Published: September 2022

Objective

This study aimed to identify the effectiveness of platelet‐rich plasma (PRP) for patients operated with anterior cruciate ligament reconstruction (ACLR).

Databases of PubMed, Embase, and CENTRAL were independently retrieved by two authors, for identifying the eligible randomized controlled trials (RCTs) comparing the clinical and imaging outcomes of ACL reconstructed patients augmented with or without PRP. The Cochrane Collaboration tool was utilized to assess the risk of bias of the included trials. We qualitatively synthesized the outcomes include the image evaluations on the healing of bone tunnels, graft remodeling, donor site healing and tunnel widening, and clinical evaluations on knee stability and function, pain symptom by visual analogue scale (VAS), inflammatory parameters and so on.

A total of 16 RCTs, including 1025 patients, were included for eligibility. Generally, the included studies were of low risk of bias, but the conducting of allocation concealment was not clearly described in many studies. Three imaging techniques, including MRI, CT and ultrasound, were selected in these trials. Significant improvement on graft remodeling, bone tunnel healing, harvest site healing and bone tunnel diameters were demonstrated in one of five (20.0%), three of five (60.0%), two of four (50.0%) and one of five (20.0%) studies respectively, for PRP group. Various clinical outcomes, such as IKDC score, Lysholm score, Tegner score, knee anteroposterior and rotational laxity, range of motion and VAS, could not be improved with PRP application.

The PRP is associated with very limited role in improving knee outcomes following ACLR, and there is no indication for PRP procedures in ACLR at this stage.
The Direct Anterior Approach versus the Posterolateral Approach on the Outcome of Total Hip Arthroplasty: A Retrospective Clinical Study
Authors: Wang Zhao , Bao Hong‐Wei , Hou Jing‐Zhao , Ju Bin , Wu Can‐Hua , Zhou Yao‐Jiang , Gu Xiao‐Ming , Wang Hai‐Hong
Published: September 2022

Objective

To compare the clinical results of the direct anterior approach (DAA) and posterolateral approach (PLA) in total hip arthroplasty (THA) patients.

Methods

From January 2017 to September 2019, 80 patients who received primary THA in our hospital were retrospectively selected based on the propensity score matching (PSM) method. Baseline characteristics of patients who underwent the DAA and PLA were collected. Moreover, the incision length, intraoperative blood loss, operative time, length of stay, and Harris hip score were compared between patients in the two groups. The CK level was used to assess muscle damage between patients in the DAA and PLA groups. The complications of these two approaches were also evaluated at patients' 12‐month follow‐up evaluation.

Results

There was no significant difference in baseline characteristics between patients in the two groups (p > 0.05). The patients in the DAA group had a shorter incision length (9.2 ± 0.2 vs 14.7 ± 0.5, respectively; p < 0.05) and shorter length of hospital stay (9.5 ± 0.7 vs 12.9 ± 0.8, respectively, p < 0.05) than patients in the PLA group. Moreover, the DAA was associated with a decrease in intraoperative blood loss compared with the PLA (109.1 ± 12.6 vs 305.1 ± 14.1 ml, respectively, p < 0.05). However, the operation time was longer in patients in the DAA group (130.7 ± 1.7) than in patients in the PLA group (112.6 ± 1.3 min, p < 0.05). The CK level of patients in the DAA group was lower than that of patients in the PLA group (p < 0.05). The CK level at 48 h post‐surgery was negatively correlated with the Harris hip scores at 6 months after THA (r = −0.538, p = 0.000). Compared with patients in the PLA group, the muscle strength of patients in the DAA group was significantly higher than that of patients in the DAA group at 4 days (p < 0.05) and 7 days (p < 0.05) after THA. The Harris hip scores of patients in the DAA group and PLA group were 81.0 ± 0.8 vs 70.8 ± 0.7 at 6 weeks, 93.4 ± 0.9 vs 86.4 ± 0.6 at 3 months, and 96.8 ± 1.1 vs 93.4 ± 0.8 at 6 months, respectively, both p < 0.05. There was no significant difference in the incidence of complications between patients in the DAA and PLA groups (p > 0.05).

Conclusion

DAA was superior to the PLA in improving hip function after THA. Compared with the PLA, the DAA could reduce muscle damage, which is negatively correlated with hip function. Further multi‐institution studies are required with longer follow‐up durations, and larger patient populations are needed to provide more definitive conclusions.
Clinical Application of Nail‐Plate Fixation in the Treatment of Complex Proximal Third Humeral Fracture: A Case Report and Literature Review
Authors: Bi Chun , Wu Jianhong , Wu Xiaoming
Published: September 2022

Background

Proximal humeral fractures with increasing incidence are common over the past decades. Among them, the complicated and displaced ones, especially combined with the proximal third humeral shaft fractures, need to be treated surgically. Humeral intramedullary nail and locking plate are the most frequently used options. However, few studies address the application of nail‐plate combination for management.

Case presentation

A 49‐year‐old man struck by a car was referred to our emergency trauma center. The X‐ray and three‐dimensional computed tomography (CT) showed a complex proximal humeral fracture with proximal third shaft fracture. No evidence of other associated injuries and neurovascular symptom of the injured left upper limb was shown by physical examination. Nail‐plate fixation was performed to restore the anatomic integrity of proximal humerus. The injured arm was maintained in a broad arm sling for 14 days after surgery. The active as well as positive movements under the instruction were encouraged as long as the pain could be tolerated from postoperative day 2. One year after the surgery, the fracture was healed, and the patient regained normal shoulder motion. The good clinical outcomes were obtained by application of nail‐plate fixation to treat complex proximal third humeral shaft fractures. Thus, this surgical intervention could be performed as an alternative.
Reduction with Pre‐Drilling Combined with a Finger Reduction Tool in Difficult‐to‐Reduce Intertrochanteric Fracture
Authors: Hu Hongxin , Chen Guoli , Wu Xianwei , Lin Mei , Lin Haibin
Published: September 2022

Objective

To investigate the feasibility of pre‐drilling combined with a finger reduction tool for the reduction of difficult‐to‐reduce intertrochanteric fractures.

Methods

Patients diagnosed with complicated intertrochanteric fractures during the period from July 2016 to May 2021 at the Affiliated Hospital of our College were enrolled in this study. All patients underwent reduction by pre‐drilling combined with a finger reduction tool followed by fixing with proximal femoral nail antirotation. The outcome of reduction was evaluated by intraoperative fluoroscopy. The operation time, intraoperative fluoroscopy frequency, and incidence of postoperative complications (including infection in the incision area, coxa vara, nail withdrawal, nail breakage, blade cut‐out, lower limb vein thrombosis, and pulmonary embolism) were recorded to evaluate the speed of the operation, the difficulty of the operation, and the prognosis of the patient, respectively. The Harris hip score at 9 months after surgery was used to evaluate the hip recovery.

Results

A total of 52 patients (17 men and 35 women), 61–88 (77.54 ± 7.40) years of age were included in the study. There were 14 patients with cardiovascular or cerebrovascular disease, ten patients with diabetes, three patients with Parkinson's disease, and three patients with respiratory diseases. The fractures included in the study were classified according to the Orthopedic Trauma Association 31 classification system as type A2.2 (n = 36) or type A2.3 (n = 16). The time from injury to surgery was 1–11 (3.35 ± 1.78) days, and the operation time ranged 31–101 (65.67 ± 14.17) min. The intraoperative blood loss ranged from 40 to 100 (67.69 ± 18.24) mL, and the number of intraoperative fluoroscopy images obtained was 12 to 32 (20.42 ± 5.27). The Harris hip score at 9 months after surgery ranged from 84 to 94 (90.06 ± 2.15). Patients were followed for 9–16 (10.63 ± 1.61) months. One patient died of acute myocardial infarction at 9 months after surgery. One patient suffered from nail withdrawal 5 months post‐operation and thus underwent hemiarthroplasty.

Conclusions

Satisfactory reduction can be achieved using a pre‐drilling femoral trochanter combined with a finger reduction tool for the management of difficult‐to‐reduce complex intertrochanteric fractures. This technique does not increase surgical trauma and also reduces the dose of radiation administered to the patient.
Clinical Comparison of the “Windowing” Technique and the “Open Book” Technique in Schatzker Type II Tibial Plateau Fracture
Authors: Ying Jichong , Yu Tianming , Liu Jianlei , Huang Dichao , Yan Hailin , Zhuang Yunqiang
Published: September 2022

Objective

Surgical treatment for Schatzker type II tibial plateau fractures remains challenging and requires high‐quality research. The aim of the study is to compare the “windowing” and “open book” techniques for the treatment of Schatzker type II tibial plateau fractures.

Methods

In this prospective study, all patients with Schatzker type II tibial plateau fractures between January 2014 and December 2017 were managed by open reduction and internal fixation using an anterolateral incision approach. “Windowing” group included 78 patients (53 men and 25 women), with an average age of 57.7 ± 13.5 years, who underwent the “windowing” technique, in which the procedure was performed through a small cortical window against the depressed zone of the lateral plateau. The “open book” group included 80 patients (56 men and 24 women), with an average age of 54.8 ± 12.4 years, who underwent the technique. The clinical outcomes included the Rasmussen classification of knee function and grading of post‐traumatic arthritis. The radiographic outcome (x‐ray and computed tomography [CT]) was the reduction quality of the lateral plateau based on the modified Rasmussen radiological assessment. The patient‐reported outcome was visual analogue scale (VAS) scores.

Results

The mean follow‐up time for the158 patients was 32 months (range, 24–42 months). The time elapsed from injury to surgery in “windowing” group and “open book” group were 3.7 ± 1.2 (range, 1–10 days) and 3.5 ± 1.4 days (range, 1–11 days), respectively, with no significant difference between the groups (P > 0.05). The operation times did not differ significantly between the “windowing” group (61.0 ± 8.3 min, range, 45–120 min) and the “open book” group (61.2 ± 10.4 min, range, 40–123 min) (P > 0.05). After surgery, CT revealed five (6.4%) and 15 (18.8%) cases of articular depression in the “windowing” and “open book” groups, respectively. Significant differences were observed in the articular depression of tibial plateau fractures between the groups (P < 0.05). However, condylar widening or valgus/varus did not differ significantly between the groups. Furthermore, no significant differences in knee function were observed during follow‐up (P > 0.05). VAS scores were similar between the groups at 24 months after surgery (P > 0.05). There were significant differences in the number of severe post‐traumatic arthritis (grades 2 and 3) cases between the groups (P < 0.05).

Conclusions

The “windowing” and “open book” techniques are both effective for the treatment of Schatzker type II tibial plateau fractures. However, the “windowing” technique provides better reduction quality, leading to a satisfactory prognosis.
Clinical and Radiological Outcomes of Revision Total Hip Arthroplasty for Patients with Prior Hartofilakidis Type C Hip Dysplasia
Authors: Guo Shengjie , Tang Hao , Ma Zhuyi , Huang Yong , Zhou Yixin
Published: September 2022

Objective

To investigate the clinical and radiological results of revision total hip arthroplasty (THA) for patients with previously diagnosed Hartofilakidis type C hip dysplasia, which is technically challenging and lacks literature.

Methods

We enrolled 20 patients with previously diagnosed Hartofilakidis type C hip dysplasia who underwent revision THA between November 2008 and July 2015 at our hospital. Patients were followed up for an average of 87 months. Data pertaining to the Harris hip score (HHS), modified Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), general satisfaction, and the level of satisfaction related to 16 hip functions or issues experienced after revision THA were collected. The vertical and horizontal center of rotation (COR) of the hips were measured bilaterally based on preoperative and postoperative anteroposterior radiographs. Categorical variables were analyzed by the chi‐square test. Continuous variables were analyzed using the student's t test or non‐parametric Wilcoxon Rank Sum test.

Results

There were significant postoperative improvements in the HHS (47.4 ± 31.6 vs 70.1 ± 39.0), modified WOMAC (48.5 ± 27.9 vs 75.7 ± 36.8), and the vertical (45.7 ± 33.7 mm vs 21.6 ± 21.8 mm) and horizontal (41.8 ± 17.0 mm vs 31.4 ± 14.7 mm) offset of the COR after revision THA (P < 0.05). Fifteen (75.0%) patients were satisfied with the procedure. The satisfaction rate for each of the 16 items ranged from 45% to 100%. The top three dissatisfactory items were squatting, getting into/out of cars, and leg‐length discrepancy. Postoperatively, dissatisfied patients had a significantly higher visual analogue scale pain score and lower WOMAC pain, HHS pain, WOMAC total, and HHS total scores, a lower satisfaction rate for pain relief, and a higher vertical COR.

Conclusion

There is a high rate (25%) of dissatisfaction with the outcome after revision THA for patients with prior Hartofilakidis type C hip dysplasia. The most likely reasons for dissatisfaction were inadequate pain relief and a higher vertical COR measured on radiography.
Healthcare professionals' perspectives on the use of medicinal cannabis to manage chronic pain: A systematic search and narrative review
Authors: Cheng Katherine Y. C. , Harnett Joanna E. , Davis Sharon R. , Eassey Daniela , Law Susan , Smith Lorraine
Published: September 2022

Rationale, aims, and objectives

Chronic pain is a global public health problem that negatively impacts individuals' quality of life and imposes a substantial economic burden on societies. The use of medicinal cannabis (MC) is often considered by patients to help manage chronic pain as an alternative or supplement to more conventional treatments, given enabling legalization in a number of countries. However, healthcare professionals involved in providing guidance for patients related to MC are often doing so in the absence of strong evidence and clinical guidelines. Therefore, it is crucial to understand their perspectives regarding the clinical use and relevance of MC for chronic pain. As little is known about attitudes of HCPs with regard to MC use for chronic pain specifically, the aim of this review was to identify and synthesize the published evidence on this topic.

Methods

A systematic search was conducted across six databases: MEDLINE, EMBASE, CINAHL, Scopus, Web of Science, and PubMed from 2001 to March 26, 2021. Three authors independently performed the study selection and data extraction. Thematic analysis was undertaken to identify key themes.

Results

A total of 26 studies were included, involving the United States, Israel, Canada, Australia, Ireland, and Norway, and the perspectives of physicians, nurses, and pharmacists. Seven key themes were identified: MC as a treatment option for chronic pain, and perceived indicated uses; willingness to prescribe MC; legal issues; low perceived knowledge and the need for education; comparative safety of MC versus opioids; addiction and abuse; and perceived adverse effects;

Conclusion

To support best practice in the use of MC for chronic pain, healthcare professionals require education and training, as well as clinical guidelines that provide evidence‐based information about efficacy, safety, and appropriate dosage of products for this indication. Until these gaps are addressed, healthcare professionals will be limited in their capacity to make treatment recommendations about MC for people/patients with chronic pain.
Pyruvate transporter BnaBASS2 impacts seed oil accumulation in Brassica napus
Authors: Tang Shan , Guo Ning , Tang Qingqing , Peng Fei , Liu Yunhao , Xia Hui , Lu Shaoping , Guo Liang
Published: September 2022

Bile acid: sodium symporter family protein 2 (BASS2) is a sodium‐dependent pyruvate transporter, which transports pyruvate from cytosol into plastid in plants. In this study, we investigated the function of chloroplast envelope membrane‐localized BnaBASS2 in seed metabolism and seed oil accumulation of Brassica napus (B. napus). Four BASS2 genes were identified in the genome of B. napus. BnaA05.BASS2 was overexpressed while BnaA05.BASS2 and BnaC04.BASS2‐1 were mutated by CRISPR in B. napus. Metabolite analysis revealed that the manipulation of BnaBASS2 caused significant changes in glycolysis‐, fatty acid synthesis–, and energy‐related metabolites in the chloroplasts of 31 day‐after‐flowering (DAF) seeds. The analysis of fatty acids and lipids in developing seeds showed that BnaBASS2 could affect lipid metabolism and oil accumulation in developing seeds. Moreover, the overexpression (OE) of BnaA05.BASS2 could promote the expression level of multiple genes involved in the synthesis of oil and the formation of oil body during seed development. Disruption of BnaA05.BASS2 and BnaC04.BASS2‐1 resulted in decreasing the seed oil content (SOC) by 2.8%–5.0%, while OE of BnaA05.BASS2 significantly promoted the SOC by 1.4%–3.4%. Together, our results suggest that BnaBASS2 is a potential target gene for breeding B. napus with high SOC.
Moderating role of coping in the association between minority stress and suicidal ideation and suicide attempts among sexual and gender minority young adults
Authors: de Lange Jennifer , Baams Laura , Bos Henny , Bosker Roel , Dumon Eva , Portzky Gwendolyn , Robinson Jo , van Bergen Diana
Published: September 2022

Objective

This study examined associations of minority stressors (i.e., victimization, internalized homonegativity, and stigma consciousness), and coping styles (i.e., active, avoidant, and passive) with suicidal ideation and suicide attempts (suicidality) among sexual and gender minority (SGM) young adults, and whether coping style moderated these associations.

Methods

Logistic regression analyses examined these associations among 1432 SGM young adults (ages 18–29).

Results

Minority stressors and passive coping were associated with a higher likelihood of suicidality. Avoidant coping was associated with a lower likelihood of lifetime suicidal ideation and attempts among sexual minority participants, and active coping with a lower likelihood of past‐year suicidal ideation among sexual minority participants. Moderation analyses among sexual minority participants showed that when avoidant coping was high, associations between low victimization (compared with no victimization) and lifetime suicide attempts, and stigma consciousness and lifetime suicide attempts became non‐significant, and the association between internalized homonegativity and lifetime suicide attempts became significant. Among gender minority participants, when passive coping was high the association between low victimization and lifetime suicidal ideation became significant.

Conclusion

This study underlines the importance of minority stress and coping for suicidality among SGM young adults and the need for more research regarding the role of coping.
The novel HLA‐B*15:638 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual
Authors: Liu Can , Zheng Zhong‐zheng , Du Ke‐ming , An Lin , Zhou Ming
Published: September 2022

HLA‐B*15:638 differs from HLA‐B*15:01:01:01 by one nucleotide in exon 2.
The novel HLA‐DQB1 allele, DQB1*06:443
Authors: Loginova Maria , Smirnova Daria , Paramonov Igor
Published: September 2022

HLA‐DQB1*06:443 differs from HLA‐DQB1*06:03:01:01 by a change in nucleotide 287.
The use of lateral arthroscopy portals for the management of bilateral osteochondritis dissecans of the radial head in an English bulldog
Authors: Shetler Samantha E. , Verpaalen Valentine D. , Hinson Whitney D. , De Lombaert Mélissa , Belhorn Stephanie A. , Giglio Robson F.
Published: September 2022

Objective

To report a case of bilateral radial head osteochondritis dissecans (OCD) in a dog treated via lateral elbow arthroscopy portals.

Study design

Case report.

Animals

Six month old female spayed English bulldog.

Methods

The dog was presented for a left thoracic limb lameness localized to the elbow. Computed tomography revealed bilaterally symmetrical mineralized fragments in the lateral compartment of the elbow joint and blunting of the medial coronoid processes. The fragments were associated with a thin donation bed along the caudolateral articular surface of the radial head with moderate surrounding subchondral bone sclerosis. Bilateral elbow arthroscopy was pursued. Arthroscopy was initiated via a standard medial approach, which allowed for abrasion arthroplasty of the radial incisure and medial coronoid process but provided insufficient access to the radial head lesions. A lateral arthroscopic approach was subsequently performed and provided excellent access to the radial head for fragment retrieval and abrasion arthroplasty.

Results

Histopathology of the radial head fragments revealed mild cartilage degeneration and retention of cartilaginous cores within subchondral bone, consistent with OCD. Complete resolution of lameness and elbow pain were observed on clinical examination 5 months postoperatively.

Conclusion

Radial head OCD can occur as a rare component of elbow dysplasia in growing dogs, and fragment retrieval with abrasion arthroplasty via lateral arthroscopic portals may be an effective treatment option.
Design and topographic evaluation of a canine humeral anatomic plating system (CHAPS) for humeral condylar fracture repair in spaniels
Authors: Burton Neil J. , Horsewill Hannah , Sparks Tim H. , Caruso Ilaria
Published: September 2022

Objective

To design a precontoured plating system for humeral condylar fracture repair in spaniels with humeral intracondylar fissure (HIF) and quantify accuracy of fit of the system on 3D printed bone models.

Study design

Experimental on 3D printed models.

Methods

The plating system was based on morphometric data obtained from CT. Plates were applied to models and impression material was measured under the plates at points of interest to define plate bone gap (PBG). Data on locking screw interference on plate application were also obtained.

Results

Eleven elbows models were plated. Statistical analysis to assess for any difference in PBG measurements between left and right humuri revealed two loci (3 and 17) under the lateral plate and two loci (3 and 17) under the medial plate. On cumulate portion analysis, 67% of lateral plate loci and 80% of medial plate loci had a PBG of ≤2 mm respectively. An incidence of 2.1% (3/143) screw interference occurred.

Conclusion

Design of a contoured plating system for application to humeral models from spaniels with HIF and its application with objective measurement of PBG is described. The majority of the loci measured under both lateral and medial plates had a BPG of ≤2 mm and the incidence of locking screw interference on plate application was low.

Clinical significance

This novel system may have application for the stabilization of humeral condylar fractures in spaniels avoiding the need for plate contouring and minimizing the incidence of locking screw interference.
A morphometric and genetic investigation of Opuntia engelmannii population variation in Africa
Authors: Mbonani Siphosenkosi , Glennon Kelsey L. , Byrne Marcus J.
Published: September 2022

Opuntia engelmannii Salm‐Dyck (Cactaceae:Opuntioideae) is a morphologically variable cactus that has invaded pasture lands in South Africa and Kenya. Biological control of invasive Opuntia species can be very successful when the correct agent is matched with the appropriate host. This research investigated the similarity (morphological and genetic) between several populations of O. engelmannii and a morphologically uniform, O. stricta, that occur in South Africa and Kenya to help understand the identity of the target weed. Spine and cladode morphology showed that the Limpopo (South African) and Kenyan populations were most similar, while the spiny Eastern Cape (South African) population was more similar to Opuntia stricta. Multivariate analysis showed that spine morphometry was a useful diagnostic character in identifying different putative O. engelmannii populations in the field. In addition, we used amplified fragments length polymorphisms to estimate genetic similarity and genetic structure among populations that represent the morphologically variable populations. There was relatively little differentiation in the population structure between the Limpopo and Kenyan populations. The spiny Eastern Cape population showed moderate genetic differentiation (FST = 0.05 − 0.15) relative to other O. engelmannii populations and was genetically more similar to the O. stricta population. These results will facilitate the search for suitable biocontrol agents by directing future collections of the appropriate biotype of Dactylopius opuntiae Cockerell (Hemiptera: Dactylopiidae) to relevant populations of O. engelmannii in its home range. In addition, given the genetic similarity of the spiny Eastern Cape population to O. stricta, we recommend the efficacy of D. opuntiae ‘stricta’ biotype be tested on the spiny Eastern Cape population as a potential biocontrol agent.
A Quantitative Study of Transport of Surfactant Boli in a Three-Dimensional Lung Model of Neonates
Authors: Combs Hannah , Shark Taylor , Heiss Jacob , Raessi Mehdi , Tavana Hossein
Published: September 2022

Neonatal respiratory distress syndrome is mainly treated with the intratracheal delivery of pulmonary surfactants. The success of the therapy depends on the uniformity of distribution and efficiency of delivery of the instilled surfactant solution to the respiratory zone of the lungs. Direct imaging of the surfactant distribution and quantifying the efficiency of delivery is not feasible in neonates. To address this major limitation, we designed an eight-generation computational model of neonate lung airway tree using morphometric and geometric data of human lungs and fabricated it using additive manufacturing. Using this model, we performed systematic studies of delivery of a clinical surfactant either at a single aliquot or at two aliquots under different orientations of the airway tree in the gravitational space to mimic rolling a neonate on its side during the procedure. Our study offers both a novel lung airway model and new insights into effects of the orientation of the lung airways and presence of a pre-existing surfactant film on how the instilled surfactant solution distributes in airways.
Maximum Likelihood Identification of Cavitation Instabilities in Axial Inducers
Authors: Tumminia Matteo , Valentini Dario , Pace Giovanni , Hadavandi Ruzbeh , Torre Lucio , Pasini Angelo , d'Agostino Luca
Published: September 2022

The article illustrates the results of an exploratory study on the effectiveness of maximum likelihood Bayesian estimation in the identification of cavitation instabilities in axial inducers using the blade-to-blade pressure measured by a single transducer flush-mounted on the impeller casing. The typical azimuthal distribution of the pressure in the blade channels is parameterized and modulated in space and time for theoretically reproducing the expected pressure generated by known forms of cavitation instabilities (cavitation surge auto-oscillations, n-lobed synchronous/asynchronous rotating cavitation, and higher-order surge/rotating cavitation modes). The power spectra of the theoretical pressure so obtained in the rotating frame are transformed in the stationary frame, corrected for frequency broadening effects, and parametrically fitted by maximum likelihood estimation to the measurements of the pressure on the inducer casing just downstream of the blade leading edges. In addition to its fundamental frequency, each form of instability generates a characteristic spectral distribution of sidebands. The identification uses this information for successfully discriminating flow oscillation modes occurring simultaneously with intensities differing by up to one order of magnitude. The method returns the estimates of the model parameters and their standard errors, allowing one to assess the accuracy and statistical significance of the identification. The results first demonstrate that elementary maximum likelihood Bayesian identification is indeed capable to effectively detect and characterize the occurrence of flow instabilities in cavitating inducers at a fraction of the experimental and postprocessing costs and complexities of traditional cross-correlation methods.
A New Approach to Estimate Particulate Matter Emissions From Ground Certification Data: The nvPM Mission Emissions Estimation Methodology
Authors: Ahrens Denise , Méry Yoann , Guénard Adrien , Miake-Lye Richard C.
Published: September 2022

Estimating nonvolatile particulate matter (nvPM)—or black carbon—emissions during an aircraft mission is extremely challenging because of the lack of reliable data in flight. For this reason, a detailed study has been undertaken to estimate in-flight emissions from data measured on the ground during engine certification. Aircraft engine emissions certification is based on the “Landing and Take-Off” (LTO) cycle developed by the Committee on Aviation Environmental Protection (CAEP) of the International Civil Aviation Organization (ICAO). It represents operations below 3000 ft. The aim of this regulation is to control and reduce pollutant emissions in the vicinity of the airport. Carbon monoxide (CO), unburnt hydrocarbon (UHC), and nitrogen oxides (NOx) have been regulated using the LTO cycle by different international standards for four decades. New certification standards on nvPM have been introduced recently. The first one, put in place in CAEP10, regulates the peak nvPM mass concentration. It has been in effect since 2020. The second set established in CAEP11 regulates the nvPM mass and number of emissions on the LTO cycle and it becomes effective in 2023. With these regulations, manufacturers are now reporting nvPM emissions data publicly. All emissions data of in-production engines, and some legacy engines, are available in the engine emissions data bank (EEDB), downloadable from the European Union Aviation Safety Agency (EASA) website. Methodologies have been proposed to estimate emissions at altitude and calculate total mission emissions for NOx, i.e., the “Boeing Fuel Flow Method” or the “DLR Döpelheuer and Lecht” methodology, which are only relying on these publicly available data from the EEDB. In the following, a new methodology for estimating nvPM emissions at altitude is proposed. The methodology was developed and validated in the framework of the CAEP technical working groups. It comprises four dedicated steps. In the present article, the different steps are explained and validation data is provided as applicable. Examples of in-production engines are analyzed, discussed, and compared against the full methodology using proprietary engine performance and emissions certification data. Following the proposed methodology, total nvPM mass and number of mission emissions can be estimated and used for emissions inventories and evaluation of climate impacts.
Power Flow Optimization for a Hybrid-Electric Propulsion System
Authors: Papadopoulos Konstantinos I. , Nasoulis Christos P. , Ntouvelos Elissaios G. , Gkoutzamanis Vasilis G. , Kalfas Anestis I.
Published: September 2022

This study deals with the optimization of performance for a hybrid-electric propulsion system. It focuses on the modeling and power management frameworks, while evaluation is done on a single flight basis. The main objective is to extract the maximum out of the novel powertrain archetype. Two hybridization factors are considered. The pair helps to describe the degree of hybridization at the power supply and power consumption levels. Their revised mathematical definition facilitates a unique method of hybrid-electric propulsion system modeling that maximizes the conveyed amount of information. An in-house computational tool is developed. It employs a genetic algorithm optimizer in the interest of managing power usage during flight. Energy consumption is set as the objective function. The operation of a 19-seater, commuter aircraft is investigated. Turbo-electric, series-hybrid, parallel-hybrid, and series-parallel variants are derived from a generic composition. An analysis on their optimized performance, with different technological readiness levels for 2020 and 2035, is aimed at identifying where each system performs best. Considering 2020 technology, it does not yield a viable hybrid-electric configuration, without suffering significant payload penalties. Architectures relying on mechanical propulsors show promise of 15% reduction to energy consumption, accounting for 2035 readiness levels. The concepts of Boundary Layer Ingestion and Distributed Propulsion display the potential to boost electrified propulsion. The series-hybrid and series-parallel configurations are the primary beneficiaries of these concepts, displaying up to 30% reduction in fuel and 20% reduction in energy consumption.
Compressor Surge Precursors for a Turbocharger Coupled to a Pressure Vessel
Authors: Silvestri Paolo , Reggio Federico , Niccolini Marmont Du Haut Champ Carlo Alberto , Ferrari Mario L. , Massardo Aristide Fausto
Published: September 2022

Dynamic compressors operating region is mainly constrained by fluid-dynamic instabilities occurring at low mass flow rate conditions, such as surge and rotating stall. This work presents a vibro-acoustic experimental investigation on a centrifugal compressor of an automotive turbocharger aimed to identify and confirm some surge precursor values in correspondence of its inception conditions. The experimental campaign was carried out on a turbocharger equipped by a vaneless diffuser compressor exploited for the pressurization of an innovative solid oxide fuel cell (SOFC) emulator. The investigated turbocharger is coupled with a pressure vessel for a former emulation activity on a pressurized SOFC. In such kind of plants, the joint effect of large volume size downstream the compressor makes more complex the dynamic behavior of the whole system during transients, thus significantly increasing surge onset risk.

The main goal is to define a suitable quantitative indicator to detect in advance surge inception by relying only on system vibro-acoustic response. Several transient from a compressor stable condition to surge instability onset were performed by progressively closing specific valves in the air line. When moving close to surge , vibro-acoustic signals were acquired at a high sampling rate to investigate blade passage phenomena which might interact with rotating stall inception. Meanwhile, pressures, temperatures and mass flow rates measured at a lower sampling rate to correlate compressor vibro-acoustic and performance behavior. Cyclostationary analysis was performed on vibro-acoustic acquired signals to provide innovative diagnostic and predictive solutions (precursors) for early surge detection.
Theoretical and Experimental Comparisons for Rotordynamic Coefficients of a Multiscratched Tilting Pad Journal Bearing
Authors: Hassini Mohamed-Amine , Zhang Silun , Chatterton Steven , Pennacchi Paolo
Published: September 2022

This paper presents a thermo-elasto-hydrodynamics model (TEHD) based on a mass conservative generalized Reynolds equation, coupled with three-dimensional (3D) energy equation for the oil film, and a full 3D thermo-mechanical model for the pads. The model uses a regularization technique to consider film thickness discontinuities created by scratches. The numerical results are compared to the experimental results obtained from a rocker-backed, five tilting pads journal bearing (TPJB) with single and multiple scratches. The numerical model achieved good agreement, especially with respect to pad temperatures and dynamic coefficients. Discrepancies were observed at low speed but only on the stiffness in the load direction. The numerical model shows a significant drop in the pressure field at the location of the scratches, and a significant pressure rise between two consecutive scratches accompanied by a decrease in film thickness.
Performance Assessment of Tesla Expander Using 3D Numerical Simulation
Authors: Renuke Avinash , Traverso Alberto
Published: September 2022

Bladeless or Tesla turbines consist of several flat parallel disks mounted on a shaft with a narrow gap between them. The analytical solution of Navier-Stokes equations for the flow between disks has been extensively studied in the past. However, there is a significant impact of the stator exit-flow conditions on the performance and flow behavior inside the rotor of the Tesla turbine. There has been limited research on flow characterization and performance evaluation of stator-rotor interaction of the Tesla expander using 3D numerical simulation. The challenge arises due to a very high aspect ratio of the Tesla rotor (diameter to gap ratio > 1000). 3D numerical modeling with a hexahedral mesh of the nozzle/stator with the commercial software is presented. The simulation is performed for a wide range of inlet pressures and rotational speeds. This work focuses on the stator performance, the stator-rotor interaction, the rotor entry losses due to disk tip, the rotor tip velocity ratio and the degree of reaction on the performance of the Tesla expander.The peak efficiency of 58% is predicted for 3 bar inlet pressure and a rotational speed of 30000 rpm for a 3 kW machine with air as a working fluid. The 3D numerical analysis provides insights on flow characterization, mainly stator-rotor interaction and flow between disks at different mass flows. Numerical results are also compared with experimented test results performed on a 100-W and a 3-kW air expander.
An Optimization Methodology for Turbines Driven by Pulsed Detonation Combustors
Authors: Asli Majid , Stathopoulos Panagiotis
Published: September 2022

A step-change in efficiency of gas turbine technology and, subsequently, an emissions reduction from this technology requires conceptual changes. Substituting conventional combustion chambers with pressure gain combustion in the form of pulsed detonation combustion (PDC) is one of the promising methods that can reduce gas turbine emissions significantly. Nevertheless, the component matching for the respective systems and specifically that of turbine expanders working with the exhaust flow of PDC tubes is still not solved. The unsteady nature of PDC exhaust flow makes 3D-CFD simulations too expensive to be applied in optimization loops in early design stages. To address this question, the present paper introduces a new cost-effective but reliable methodology for turbine analysis and optimization, based on the unsteady exhaust flow of pulsed detonation combustors. The methodology unitizes a robust unsteady one-dimensional solver, a meanline performance analysis, and an adaptive surrogate optimization algorithm. A two-stage axial turbine is optimized considering all unsteady flow features of a hydrogen-air PDC configuration with five PDC tubes. A three-dimensional URANS simulation is performed for the optimized geometry and the baseline to evaluate the methodology. The results showed that the optimized turbine produces 16% lower entropy than the original one. Additionally, the turbine output power is increased by 14% by the optimized design. Based on the results, it is concluded that the approach is fast and reliable enough to be applied in optimizing any turbine working with unsteady flows, more specifically in PDC applications.
Investigating the Mixture Quality in Multi-Injector Burner Systems—Part I: Experimental Setup
Authors: Macias Fabian Marquez , Hirsch Christoph , Sattelmayer Thomas , Huth Michael , Meisl Jürgen
Published: September 2022

A new approach to calculate the mixture statistics in multi-injector burner (MIB) systems from a single injector database is presented in the paper. In such systems, the mixture quality is highly sensitive to the flowrate and the skewness of the inflow velocity profile. To determine the mixture fraction statistics from these two parameters for a particular injector in a multi-injector configuration, output-based proper orthogonal decomposition (O-POD) is suggested using results from Reynolds-averaged Navier Stokes (RANS)–computational fluid dynamics (CFD) as the observable. The O-POD mixing database is determined experimentally from two setups: First, the mixture quality in a single injector at ideal inflow conditions is studied. Then the same injector type is investigated in a generic MIB system. To characterize the mixture quality, the mixing probability mass function (PMF) at the injector exit is measured by means of laser-induced fluorescence (LIF) and high speed imaging. The data obtained for both the single injector under ideal inflow and the MIB are presented. These studies of the mixture behavior reveal that an asymmetric inflow velocity profile leads to a significant increase of unmixedness, which is seen as a negative skewness of the mixing PMFs. This effect becomes stronger at higher momentum flux density ratios due to the higher penetration depth of the fuel jets. The application of the O-POD to the database shows that the PMF can be accurately modeled with only three modes.
Stability Analysis of an Industrial Blade Accounting for a Blade-Tip/Casing Nonlinear Interface
Authors: Colaïtis Yann , Batailly Alain
Published: September 2022

This paper investigates the local stability analysis of periodic solutions corresponding to the nonlinear vibration response of an industrial compressor blade, NASA rotor 37, on which are applied different types of nonlinearities. These solutions are obtained using a harmonic balance method-based approach presented in a previous paper. It accounts for unilateral contact and dry friction of the rotating blade against a rigid casing through a regularized penalty law. A Lanczos filtering technique is also employed to mitigate spurious oscillations related to the Gibbs phenomenon thus enhancing the robustness of the solver. In addition, a component mode synthesis technique is used to reduce the dimension of the numerical model. Stability assessment of the computed solutions relies on Floquet theory. It is performed through the computation of the monodromy matrix as well as Hill's method. Both methodologies are applied and thoroughly compared as the severity of the nonlinearity is gradually increased from a cubic spring to three-dimensional contact conditions on a deformed casing. While the presented results underline the applicability of both stability assessment methodologies for all types of nonlinearities, they also put forward the much higher computational effort required when computing the monodromy matrix. Indeed, it is shown that Hill's method yields converged results for significantly lower values of both the number of retained harmonics and the considered number of time steps thus making it a far more efficient method when dealing with industrial models. It is also underlined that the presented results are in excellent agreement with reference solution points obtained with time domain solution methods. Specific implementation tweaks that were found to be of critical importance in order to efficiently assess the stability of computed solutions are also detailed in order to provide a comprehensive view of the challenges inherent to such numerical developments.