bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing the filamentary nature of star formation in the California giant molecular cloud
Authors: Zhang Guo-Yin , André Philippe , Men’shchikov Alexander , Li Jin-Zeng
Published: July 2024

Context. Recent studies suggest that filamentary structures are representative of the initial conditions of star formation in molecular clouds and support a filament paradigm for star formation, potentially accounting for the origin of the stellar initial mass function (IMF). The detailed, local physical properties of molecular filaments remain poorly characterized, however.

Aims. Using Herschel imaging observations of the California giant molecular cloud, we aim to further investigate the filament paradigm for low- to intermediate-mass star formation and to better understand the exact role of filaments in the origin of stellar masses.

Methods. Using the multiscale, multiwavelength extraction method getsf, we identify starless cores, protostars, and filaments in the Herschel data set and separate these components from the background cloud contribution to determine accurate core and filament properties.

Results. We find that filamentary structures contribute approximately 20% of the overall mass of the California cloud, while compact sources such as dense cores contribute a mere 2% of the total mass. Considering only dense gas (defined as gas with AV,bg > 4.5–7), filaments and cores contribute ~66–73% and 10–14% of the dense gas mass, respectively. The transverse half-power diameter measured for California molecular filaments has a median undeconvolved value of 0.18 pc, consistent within a factor of 2 with the typical ~0.1 pc width of nearby filaments from the Herschel Gould Belt survey. A vast majority of identified prestellar cores (~82–90%) are located within ~0.1 pc of the spines of supercritical filamentary structures. Both the prestellar core mass function (CMF) and the distribution of filament masses per unit length or filament line mass function (FLMF) are consistent with power-law distributions at the high-mass end, ΔN/ΔlogM ∝ M−1.4±0.2 at M > 1 M⊙ for the CMF and ΔN/Δlog Mline ∝ Mline−1.5±0.2 for the FLMF at Mline > 10 M⊙ pc−1, which are both consistent with the Salpeter power-law IMF. Based on these results, we propose a revised model for the origin of the CMF in filaments, whereby the global prestellar CMF in a molecular cloud arises from the integration of the CMFs generated by individual thermally supercritical filaments within the cloud.

Conclusions. Our findings support the existence a tight connection between the FLMF and the CMF/IMF and suggests that filamentary structures represent a critical evolutionary step in establishing a Salpeter-like mass function.
The atmospheric composition of the ultra-hot Jupiter WASP-178 b observed with ESPRESSO
Authors: Damasceno Y. C. , Seidel J. V. , Prinoth B. , Psaridi A. , Esparza-Borges E. , Stangret M. , Santos N. C. , Zapatero-Osorio M. R. , Alibert Y. , Allart R. , Azevedo Silva T. , Cointepas M. , Costa Silva A. R. , Cristo E. , Di Marcantonio P. , Ehrenreich D. , González Hernández J. I. , Herrero-Cisneros E. , Lendl M. , Lillo-Box J. , Martins C. J. A. P. , Micela G. , Pallé E. , Sousa S. G. , Steiner M. , Vaulato V. , Zhao Y. , Pepe F.
Published: July 2024

Context. Ultra-hot Jupiters (UHJ) have emerged as ideal testbeds for new techniques for studying exoplanet atmospheres. Only a limited number of them are currently well studied, however.

Aims. We search for atmospheric constituents for the UHJ WASP-178 b with two ESPRESSO transits. Additionally, we show parallel photometry that we used to obtain updated and precise stellar, planetary, and orbital parameters.

Methods. The two transits we obtained were analysed with narrow-band transmission spectroscopy and with the cross-correlation technique to provide detections at different altitude levels. We focused on searching for Na I, Hα, Hβ, Hγ, Mg I, and Li I lines in narrow-band data, as well as Fe I and Fe II, and attempted to confirm Mg I with the cross-correlation technique. We corrected for the Rossiter-McLaughlin effect and regions with a low signal-to-noise ratio due to Na I absorption in the interstellar medium. We then verified our results via bootstrapping.

Results. We report the resolved line detections of Na I (5.5σ and 5.4σ), Hα (13σ), Hβ (7.1σ), and tentatively Mg I (4.6σ). With a cross-correlation, we confirm the Mg I detection (7.8 σ and 5.8 σ), and we additionally report the detections of Fe I (12σ and 10σ) and Fe II (11σ and 8.4σ) on both nights separately. The detection of Mg I remains tentative, however, because the results on the two nights differ. The results also differ compared with the properties derived from the narrow-band data.

Conclusions. None of our resolved spectral lines probing the middle to upper atmosphere shows significant shifts relative to the planetary rest frame. Hα and Hβ exhibit a respective line broadening of 39.6 ± 2.1 km s−1 and 27.6 ± 4.6 km s−1, however, indicating the onset of possible escape. WASP-178 b differs from similar UHJ by its lack of strong atmospheric dynamics in the upper atmosphere. The broadening seen for Fe I (15.66 ± 0.58 km s−1) and Fe II (11.32 ± 0.52 km s−1) might indicate the presence of winds in the mid-atmosphere, however. Future studies of the impact of the flux variability caused by the host star activity might shed more light on the subject. Previous work indicated the presence of SiO cloud-precursors in the atmosphere of WASP-178 b and a lack of Mg I and Fe II. However, our results suggest that a scenario in which the planetary atmosphere is dominated by Mg I and Fe II is more likely. In light of our results, we encourage future observations to further elucidate these atmospheric properties.
Testing a non-local 1-equation turbulent convection model: A solar model
Authors: Braun T. A. M. , Ahlborn F. , Weiss A.
Published: July 2024

Context. Turbulent convection models treat stellar convection more physically than standard mixing-length theory by including non-local effects. We recently successfully applied the Kuhfuss version to convective cores in main sequence stars. Its usefulness for convective envelopes remains to be tested.

Aims. The solar convective envelope constitutes a viable test bed for investigating the usefulness of the 1-equation Kuhfuss turbulent convection model.

Methods. We used the one-dimensional stellar evolution code GARSTEC to calculate a standard solar model with the 1-equation Kuhfuss turbulent convection model, and compared it to helioseismic measurements and a solar model using standard mixing-length theory. Additionally, we investigated the influence of the additional free parameters of the convection model on the solar structure.

Results. The 1-equation Kuhfuss model reproduces the sound-speed profile and the lower boundary of the convective region less well than the mixing-length model, because the inherent non-local effects overestimate the amount of convective penetration below the Schwarzschild boundary. We trace this back to the coupling of the temperature gradient to the convective flux in the 1-equation version of the Kuhfuss theory.

Conclusions. The temperature stratification of the solar convective envelope is not well modelled by the 1-equation Kuhfuss turbulent convection model, and the more complex 3-equation version is needed to improve the modelling of convection in the envelopes of 1D stellar evolution models.
The Role of Hysteroscopy in the Assessment of Fallopian Tubal Patency: A Comprehensive Review and Meta-analysis
Authors: Hager Marlene , Ott Johannes
Published: July 2024

Hysteroscopy has been recognized as a reliable method for the evaluation of female infertility for several years. The outpatient setting is particularly convenient, as patients do not require general anesthesia and do not have to stay overnight. In recent years, more and more articles have dealt with the role of diagnostic hysteroscopy in tubal evaluation. Twenty-four articles were included in this comprehensive review and 14 of them were also included in a meta-analysis. This review provides an overview of the different techniques of hysteroscopic tubal evaluation, with a focus on perioperative changes in cul-de-sac volume, the air bubble technique (“Parryscope” technique), the Flow technique and selective hysteroscopic pertubation with methylene blue dye (SHPMBD). In pooled analyses, SHPMBD achieved the highest sensitivity for tubal patency (91.7%, 95% confidence interval, CI: 88.8–94.0), whereas the air bubble technique revealed the highest specificity of all methods
(98.4, 95% CI: 95.3–99.6). Furthermore, in a meta-analysis of all methods on the assessment of single tubes, an overall sensitivity of 87.1% and an overall specificity of 79.8% (95% CI: 76.4–82.9) could be shown. In conclusion, the techniques of hysteroscopic tubal evaluation are well-tolerated, clinically relevant, and reliable.
Abaloparatid – eine neue osteoanabole Therapieoption für die
Osteoporose bei postmenopausalen Frauen
Authors: Kann Peter Herbert , Hadji Peyman , Kurth Andreas , Schmidmaier Ralf , Thomasius Friederike
Published: July 2024

Abaloparatid ist ein synthetisches Strukturanalogon des Parathormon-verwandten
Peptids (PTHrP). Durch Bindung an Parathormon-1-Rezeptor stimuliert es
Osteoblasten zum Knochenaufbau, dies bei einer geringeren begleitenden
Osteoklastenstimulation, so dass in der Summe ein größerer osteoanaboler
Nettoeffekt im Vergleich zu Teriparatid resultiert. Auch klinisch ist es
mindestens so stark wirksam wie Teriparatid, möglicherweise diesem sogar
überlegen, wobei hier unmittelbare head-to-head Studien derzeit nicht vorliegen.
Abaloparatid reduziert effektiv das Auftreten vertebraler und peripherer
osteoporotischer Frakturen mit auch entsprechenden günstigen Effekten auf die
Knochendichte und die Knochenumbaumarker. Zu beachten ist, dass nach der
subcutanen Injektion ein moderater Anstieg der Herzfrequenz beobachtet werden
kann, wobei es aber keine Anhaltspunkte dafür gibt, dass dies mit
schwerwiegenderen kardiovaskulären Komplikationen zu assoziieren wäre.
Abaloparatid (Eladynos) wurde in Europa zur Behandlung der Osteoporose bei
postmenopausalen Frauen mit erhöhtem Frakturrisiko für eine Therapiedauer von 18
Monaten zugelassen. Nachfolgend ist die Durchführung einer
osteoklasteninhibierenden Bisphosphonattherapie als Sequenz zu empfehlen.
Surgical Treatment of Patients with Endometriosis in the Certified Endometriosis Centers of the DACH Region – A Subanalysis of the Quality Assurance Study QS ENDO pilot
Authors: Zeppernick Felix , Zeppernick Magdalena , Wölfler Monika Martina , Janschek Elisabeth , Holtmann Laura , Bornemann Sebastian , Oehmke Frank , Salehin Darius , Scheible Chi Mi , Brandes Iris , Vingerhagen-Pethick Sigrid , Cornelius Claus-Peter , Boosz Alexander , Krämer Bernhard , Sillem Martin , Keckstein Jörg , Schweppe Karl-Werner , Meinhold-Heerlein Ivo ,   for the QS ENDO Working Group of the Endometriosis Research Foundation (SEF)
Published: July 2024

Introduction After puberty, at least 10% of all women and girls suffer from endometriosis. Surgery is useful for both the diagnosis and therapy. To date, quality indicators for the surgical treatment of endometriosis are lacking. QS ENDO aims to record the quality of care provided in the DACH region and to introduce quality indicators for the diagnosis and treatment of endometriosis. In the first phase of the study, QS ENDO real, the reality of care was recorded using a questionnaire. The second phase, QS ENDO pilot, investigated the treatment of patients who underwent surgery in certified endometriosis centers in a defined time-period.

Material and Methods The surgical data of 10 patients from each of the 44 endometriosis centers in the DACH region was recorded using an online tool. Collected data included the approach used, the endometriosis phenotype, a description of the surgical site, resection status, histological confirmation, the use of a classification, and any complications. All operations were carried out in October 2016 as the defined time-period. The surgical approaches used were compared with the recommendations in the current guidelines.

Results The data of 435 patients with a median age of 34 years were evaluated. 315 (72.4%) were nulliparous. 120 patients had given birth to at least one child and 42.5% (51) of them had delivered their child by caesarean section. About 50% of all patients also had deep infiltrating endometriosis in addition to ovarian endometriosis, and the median NAS score was 7.5. With regards to the surgical treatment, endometriomas were completely resected in 81% (94) of patients. 87.3% of patients underwent resection of peritoneal endometriosis. Forty-one patients had a hysterectomy, with a total hysterectomy carried out in 26 (63.4%) and a supracervical hysterectomy in 15 (36.6%) patients. Of the 59 patients with bowel endometriosis, half had segmental resection and half had shaving of the anterior rectal wall. Complications requiring revision occurred in 0.9% of cases.

Conclusion The surgical procedures carried out in the certified endometriosis centers of the DACH region are largely in line with the recommendations for appropriate surgical approaches in the current standard guidelines.
Comparison of 8th and 7th editions of TNM staging in terms of mortality, persistent disease, and response to treatment in patients with differentiated thyroid cancer
Authors: Gholami Golnaz , Aghaee Atena , Shafiei Susan , Rasoulian Bashir , Askari Emran , Zare Namdar Samira , Zakavi Seyed Rasoul
Published: July 2024

Objective To compare the eighth and seventh editions of TNM
staging (TNM-8 and TNM-7) on disease-related mortality, persistent disease, and response to
treatment in patients with differentiated thyroid cancer (DTC).

Methods and Materials We studied 400 patients (79% female) with
DTC with a mean age of 40.93±14.11 years. TNM staging was recorded according to the 7th and
8th editions and patients were followed for at least 1 year and response to therapy was
recorded according to ATA response categorization.

Results The mean follow up time was 42.5±15.24 months. Overall,
108 patients (27%) were down-staged using the TNM-8, mainly due to the changes in the age
cut-off (14.5%), N (9.25%), and T categorization (3.25%). All patients in stage III and 82.8%
in stage IV were down-staged. The mean Tg levels were significantly higher in stages III and
IV in TNM-8 compared to TNM-7. Four disease-related death were recorded during follow up, all
in stage IV according to TNM-7, while one was in stage II according to TNM-8. One year after
treatment, persistent disease was detected in 12% and 77% of patients in stage III according
to the 7th and 8th editions, respectively (P= 0.04). Similarly, biochemical incomplete
response one year after treatment was seen in 7.3% and 87% in stage III disease using 7th and
8th editions (P = 0.006) that fell to 2.4% and 22% in the last visit respectively (P =
0.04).

Conclusion Persistent disease and incomplete response to therapy
were more common in stages III and IV in TNM-8 compared to TNM-7. The eighth edition was a
better predictor of persistent disease in stages III and IV disease.
Mobile Rehabilitation erweitert denken – zur Implementierung einer
Mobilen indikationsübergreifenden Rehabilitation
Authors: Wilke Cornelia , Siegert Rudolf , Warnach Martin , Beyer Joachim , Emmerich Jan , Reckert Matthias , Kasprick Lysann , Liebl Max Emanuel , Schmidt-Ohlemann Matthias
Published: July 2024

Der Berufsverband für Physikalische und Rehabilitative Medizin (BVPRM), die
Deutsche Gesellschaft für Physikalische und Rehabilitative Medizin (DGPRM) und
die Bundesarbeitsgemeinschaft Mobile Rehabilitation (BAG MoRe) plädieren für die
Weiterentwicklung der mobilen Rehabilitation durch ein Konzept einer mobilen
indikationsübergreifenden Rehabilitation außerhalb der Geriatrie. Dieses sollte
für Menschen mit komplexen Schädigungen entwickelt und erprobt werden.
Environmental footprint and material composition comparison of single-use and reusable duodenoscopes
Authors: López-Muñoz Pedro , Martín-Cabezuelo Rubén , Lorenzo-Zúñiga Vicente , García-Castellanos Marina , Vilariño-Feltrer Guillermo , Tort-Ausina Isabel , Campillo-Fernández Alberto , Pons Beltrán Vicente
Published: July 2024

Background Infection outbreaks associated with contaminated reusable duodenoscopes (RUDs) have induced the development of novel single-use duodenoscopes (SUDs). This study aimed to analyze the material composition and life cycle assessment (LCA) of RUDs and SUDs to assess the sustainability of global and partial SUD implementation.

Methods A single-center study evaluated material composition analysis and LCA of one RUD and two SUDs from different manufacturers (A/B). Material composition analysis was performed to evaluate the thermochemical properties of the duodenoscope components. The carbon footprint was calculated using environmental software. We compared the sustainability strategies of universal use of RUDs, frequent use of RUDs with occasional SUDs, and universal use of SUDs over the lifetime of one RUD.

Results RUDs were substantially heavier (3489 g) than both SUD-A (943 g) and SUD-B (716 g). RUDs were mainly metal alloys (95%), whereas SUDs were mainly plastic polymers and resins (70%–81%). The LCA demonstrated the sustainability of RUDs, with a life cycle carbon footprint 62–82 times lower than universal use of SUDs (152 vs. 10 512–12 640 kg CO2eq) and 10 times lower than occasional use of SUDs (152 vs. 1417–1677 kg CO2eq). Differences were observed between SUD-A and SUD-B (7.9 vs. 6.6 kg CO2eq per endoscope). End-of-life incineration emissions for SUDs were the greatest environmental contributors.

Conclusions Widespread adoption of SUDs has greater environmental challenges; it requires a balance between infection control and environmental responsibility. Carbon footprint labelling can help healthcare institutions make sustainable choices and promote environmentally responsible healthcare practices.
WHO-Leitlinie zur Kohlenhydratzufuhr für Erwachsene und
Kinder
Authors: Sommer Isolde , Nußbaumer-Streit Barbara , Gartlehner Gerald
Published: July 2024

Hintergrund Nicht-übertragbare Krankheiten sind weltweit für die meisten
Todesfälle verantwortlich. Ungesunde Ernährung wird dabei als wichtiger
Risikofaktor angesehen. Unter anderem steht die Qualität der Kohlenhydrate in
der Ernährung in Zusammenhang mit einem erhöhten Risiko nicht-übertragbarer
Krankheiten. Der Anteil an Ballaststoffen ist ein besonders wichtiger Indikator
für die Qualität von Kohlenhydraten.

Ziel Ziel dieser Leitlinie der Weltgesundheitsorganisation (WHO) ist es,
Empfehlungen zur Kohlenhydratzufuhr, einschließlich der Ballaststoffzufuhr und
der gesunden Kohlenhydratquellen, zu erstellen.

Methode Die Leitlinie wurde gemäß des WHO-Handbuchs für die Entwicklung
von Leitlinien entwickelt. Der Prozess beinhaltet eine Überprüfung der
systematisch erfassten Evidenz durch eine internationale, multidisziplinäre
Expert*innengruppe, eine Bewertung des Vertrauens in diese Evidenz anhand des
GRADE (Grading of Recommendations, Assessment, Development and Evaluation) –
Ansatzes und die Berücksichtigung zusätzlicher Faktoren bei der Formulierung von
Empfehlungen

Ergebnisse Die Ergebnisse von sieben systematischen Übersichtsarbeiten
informierten die Formulierung der Empfehlungen zur Kohlenhydratzufuhr. Die WHO
empfiehlt, dass die Kohlenhydratzufuhr hauptsächlich aus Vollkornprodukten,
Gemüse, Obst und Hülsenfrüchten bestehen sollte. Weiters empfiehlt sie für
Erwachsene eine Zufuhr von mindestens 400 g Gemüse und Obst pro Tag, für Kinder
und Jugendliche je nach Alter mindestens 250–400 g pro Tag. Bezüglich natürlich
vorkommender Ballaststoffe wird für Erwachsene eine tägliche Zufuhr von
mindestens 25 g, für Kinder und Jugendliche je nach Alter 15–25 g pro Tag
empfohlen.
Role of Interventional Radiology in Managing Primary and Metastatic Breast Cancer
Authors: Deipolyi Amy R. , Ward Robert C.
Published: July 2024

Percutaneous image-guided locoregional therapies are emerging in the treatment of primary and metastatic breast cancer. Cryoablation has emerged as the dominant ablative approach as an alternative to surgery for primary breast cancer in patients who do not wish to have surgery or are poor surgical candidates. Cryoablation is well tolerated and provides excellent local control and cosmesis. Thermal ablation may also be used in the treatment of oligometastatic breast cancer, allowing patients to achieve long disease-free intervals. Transarterial therapies have been studied in the treatment of oligoprogressive hepatic metastasis, though further supportive data would be helpful to demonstrate its efficacy.
Local Treatment of Desmoid Tumors: An Update
Authors: Quek Lawrence Han Hwee , Chan Lester Wai Mon , Pua Uei
Published: July 2024

Desmoid tumors (DTs) are rare fibroblastic proliferations, characterized by infiltrative growth and a propensity for local recurrence. Traditional strategies such as surgery, radiotherapy, and chemotherapy are the mainstays of treatment, each with its limitations and associated risks. The trend in DT management leans toward a “wait-and-see” strategy, emphasizing active surveillance supported by continuous MRI monitoring. This approach acknowledges the unpredictable nature of the disease, and a multidisciplinary management of DT requires a nuanced approach, integrating traditional therapies with emerging interventional techniques. This review highlights the emerging role of minimally invasive interventional radiological technologies and discusses interventional radiology techniques, including chemical, radiofrequency, microwave, cryoablation, and high-intensity focused ultrasound ablations as well as transarterial embolization.
Recent Advances in Minimally Invasive Management of Osteolytic Periacetabular Skeletal Metastases
Authors: Jiang Will , Lee Sangmin , Caruana Dennis , Zhuang Kun Da , Cazzato Roberto , Latich Igor
Published: July 2024

Painful skeletal osteolytic metastases, impending pathological fractures, and nondisplaced fractures present as a devastating clinical problem in advanced stage cancer patients. Open surgical approaches provide excellent mechanical stabilization but are often associated with high complication rates and slow recovery times. Percutaneous minimally invasive interventions have arisen as a pragmatic and logical treatment option for patients with late-stage cancer in whom open surgery may be contraindicated. These percutaneous interventions minimize soft tissue dissection, allow for the immediate initiation or resumption of chemotherapies, and present with fewer complications. This review provides the most up-to-date technical and conceptual framework for the minimally invasive management of osseous metastases with particular focus on periacetabular lesions. Fundamental topics discussed are as follows: (1) pathogenesis of cancer-induced bone loss and the importance of local cytoreduction to restore bone quality, (2) anatomy and biomechanics of the acetabulum as a weight-bearing zone, (3) overview of ablation options and cement/screw techniques, and (4) combinatorial approaches. Future studies should include additional studies with more long-term follow-up to better assess mechanical durability of minimally invasive interventions. An acetabulum-specific functional and pain scoring framework should be adopted to allow for better cross-study comparison.
Effects of Parental-Group Intervention on Parents' Growth Mindset and Behaviors of Children with Attention Deficit Hyperactivity Disorder
Authors: Fuengfoo Adidsuda , Poonsawat Rawiwan , Leelathanaporn Sija , Mekrungcharas Thanyaporn
Published: July 2024

Attention deficit hyperactivity disorder (ADHD) is the most common developmental disorder among school-aged children. A multimodal treatment approach is the most effective approach for ADHD children. Parent intervention group activities help parents with ADHD children develop a good mindset toward their child and help develop skills to design appropriate parenting strategies. Our objective was to study the effect of growth mindset activities on reducing behavioral problems of ADHD children and factors associated with stress among parents of children with ADHD. A randomized controlled trial was conducted and parents of ADHD children aged 7 to 15 years were divided into the experimental and the control groups. The experimental group participated in mindset and communication intervention activities for 3 hours each, while the control group received only initial knowledge and guidance. Baseline data were collected in the beginning of the trial and at 2 and 6 months after starting the trial. Fifty parents with a mean age of 40.14 ± 8.28 years were divided into two groups. After 6 months, the mean mindset scores of the experimental group were statistically significantly higher than those of the control group (p-value = 0.014) and the impulsiveness score decreased by 2.46 ± 1.19 points (p-value = 0.05). The associated factors affecting parenting stress are their own mindset and their child's rebellious behavior. Parent intervention group activities help adjusting parents' mindsets and reduce impulsive behavior in children at 6 months of the trial. A child's rebellious behavior is the best predictor of parental stress, followed by the parents mindset.
An Unusual Case of Teeth in Neck: An Interesting Case Report
Authors: Wadhwa Vikram , Tandon Swati , Singh Maya , Bapat Daamini
Published: July 2024

Background Foreign bodies of neck are a common occurrence after trauma and road traffic accidents. Foreign bodies can get lodged in the neck especially after open wound. These could range from a piece of glass, wood, pebble pieces, or the part of tool used for trauma.

Case Presentation We report a case of an unusual foreign body in the neck. Posttrauma, patient had mandibular fracture with dislodgement of teeth in the neck masquerading as foreign body. Patient required surgical intervention for removal of teeth from the neck via an external incision and recovered uneventfully.

Conclusion The aim of the article was to highlight the importance of complete clinical and radiological examination in a patient of trauma. Missing teeth especially in cases of mandibular fracture must be searched for carefully.
20.5.1.2.9 Synthesis of Esters from Carboxylic Acids and Derivatives (Update 2024)
Authors: de Figueiredo R. M.
Published: July 2024

This review is a further update to the earlier Science of Synthesis contributions detailing the preparation of carboxylic acid esters from the corresponding acids and other derivatives [Sections 20.5.1.2 (2007) and 20.5.1.2.8 (2011)], and considers relevant esterification methods that were not covered in those previous chapters or have been reported since then. Protocols for the synthesis of esters from carboxylic acids and alcohols, alkyl halides (and surrogates), alkenes, or allenes are included. Moreover, ester formation through C(sp3)—H functionalization and from carboxylic acid derivatives, such as N-acyloxazolidinones and amides, are also covered.
20.2.1.3.6 Synthesis of Carboxylic Acids from Aldehydes and Ketones (Update 2024)
Authors: Favre-Réguillon A.
Published: July 2024

This chapter is an update to the earlier Science of Synthesis contribution (Section 20.2.1.3) and describes methods for the formation of carboxylic acids reported in the period 2007–2023. The focus is on recent advances in the synthetic preparations of carboxylic acids from aldehydes and ketones using green and sustainable reagents as well as continuous flow procedures.
20.2.1.9 Synthesis of Alkanoic Acids Using Carbon Dioxide through Catalytic C—C Bond-Forming Reactions
Authors: Rawat V. K. , Mita T.
Published: July 2024

In recent years, there has been growing interest in utilizing carbon dioxide as a feedstock for organic synthesis due to its abundance, low cost, and environmentally benign nature, with a particular focus on the catalytic synthesis of alkanoic acids from readily available starting materials via C–C bond formation. This review provides a comprehensive overview of this approach, covering the synthesis of alkanoic acids from alkyl (pseudo)halides, alkyl alcohol derivatives, isolable organometallic species, alkenes, and alkanes via C(sp3)–H bond activation. The versatility and practicality demonstrated for these methods underscores the significance of this approach in accessing valuable carboxylic acid derivatives from carbon dioxide.
22.2.5 Selenocarboxylic Acids and Derivatives (Update 2024)
Authors: Murai T.
Published: July 2024

Selenocarboxylic acids and their derivatives are the selenium isologues of carboxylic, thioic, carbamic, and carbonic acids, and the corresponding esters, amides, and ureas, and are distinguished by the presence of a C=Se bond. The synthesis of these selenium analogues primarily involves incorporating selenium atoms into precursor molecules. This can be achieved by reducing elemental selenium to produce Se2– species, which are then introduced into electrophilic species. Alternatively, carbon nucleophiles can directly bond with elemental selenium, forming carbon–selenium bonds. Compounds containing a P=Se bond, such as Woollins’ reagent, are used to substitute the oxygen in a C=O bond with selenium, creating a C=Se bond. Carbon diselenide (CSe2) is another agent used in synthesizing these derivatives. However, extreme caution is required when handling CSe2 due to its potent odor and toxicity.
22.3.5 Tellurocarboxylic Acids and Derivatives (Update 2024)
Authors: Murai T.
Published: July 2024

Tellurocarboxylic acids and their derivatives are tellurium isologues of carboxylic acids, esters, amides, carbonates, and carbamates wherein an oxygen atom of the C=O group in the original compounds is replaced with a tellurium atom. Their stabilities are generally low, and almost no new synthetic methods for them have been reported recently, although some theoretical studies have been published. Nevertheless, iminium salts generated from amides and selenoiminium salts are converted into telluroamides with a tellurating agent prepared from elemental tellurium and lithium aluminum hydride.
33.1.8.2 Alk-1-enyl Sulfides (Update 2024)
Authors: Kwiatkowska M. , Kiełbasiński P.
Published: July 2024

Alk-1-enyl sulfides are an interesting class of compounds that are widely used in organic synthesis. There are a large variety of methods for their preparation, employing both substrates and reagents as the sulfur source. Most recent advances (in the period 2006–2022) reported for the synthesis of alk-1-enyl sulfides have involved the preparation of variously substituted derivatives of the title compounds. The substituents include halogens (fluorine and polyfluoroalkyls, chlorine, bromine, and iodine), the nitro group, and acyloxy, ester, carboxy, sulfonyl, and amino groups. The application of various sulfur sources and synthetic strategies to form alk-1-enyl sulfides, and finally the synthesis of cyclic alk-1-enyl sulfides and polyene alk-1-enyl sulfides are also reported.
35.3.5.6 Synthesis of 1-Iodo-n-Heteroatom-Functionalized Alkanes (n ≥2) by Addition across C—X (X = O, N, S) or C—C Bonds (Update 2024)
Authors: Marciniszyn J. P. , Kretzschmar M. , Gulder T.
Published: July 2024

This review updates the previous Science of Synthesis contributions on the synthesis of 1-iodo-n-heteroatom-functionalized alkanes (n ≥2) that are formed by addition across C—O (Section 35.3.5.2), C—N (Section 35.3.5.3), C—S (Section 35.3.5.4), or C—C bonds (Section 35.3.5.5). Methods reported between 2007 and 2023 are described, with a focus on the ring opening of three- or four-membered cyclic systems.
Compact hard x-ray flash radiography device based on wire-shorted low-impedance rod pinch diode
Authors: Wang Tongquan , Shi Huantong , Zhang Peizhou , Wang Yizhu , Wang Dongsheng , Xu Ming , Li Xingwen , Wu Jian , Qiu Aici
Published: July 2024

A rod pinch diode (RPD) is a feasible load configuration to generate a high-brightness, small-size hard x-ray radiation source. In this paper, the radiography performance of a wire-shorted low-impedance RPD on a compactly designed table-top driver (WRPD-1) is demonstrated for the first time. The driver consists of four high-power discharge branches connected in parallel, with each branch consisting of two metal-film capacitors and one multigap field-distortion switch in series. The four branches are triggered synchronously to generate a fast-rising current pulse: the inductance of the load section at the short circuit is ∼10 nH, and the short-circuit current amplitude is ∼325 kA at ±90 kV charging voltage, with a 10%–90% rise time of 110 ns. With a low-impedance RPD shorted by an 18-µm-diameter aluminum wire, a quasi-spherical x-ray focal spot with diameter <0.6 mm (width of the half-maximum grayscale) and a pulse duration of ∼25 ns (half-width of the radiation pulse) is obtained at ±70 kV charging voltage, and the imaging resolution excels 10 lp/mm under 1.56× magnification. According to the transmission–absorption x-ray spectrum estimation, the average emitted photon energy is ∼30 keV with a distinct peak in the 10–15 keV range that corresponds to the L-lines of tungsten, and the total energy of photons >10 keV reaches ∼1.16 J. The present results show that the device can serve well for the flash radiography diagnosis and potentially as an efficient light source for dynamic x-ray diffraction.
The steady Prandtl boundary layer expansions for non-shear Euler flow
Authors: Gao Chen , Zhang Liqun
Published: July 2024

We continue the study on the validity of the Prandtl boundary layer expansions in [Gao et al., Sci. China Math. 66, 679–722 (2023)], whereby estimating the stream-function of the remainder, we proved the case when the Euler flow is the perturbation of shear flow in a narrow domain. In this paper, we obtain a new derivatives estimate of stream-function away from the boundary layer and then prove the validity of expansions for any non-shear Euler flow, provided that the width of the domain is small.
Model adaptive phase space reconstruction
Authors: Dhadphale Jayesh M. , Hauke Kraemer K. , Gelbrecht Maximilian , Kurths Jürgen , Marwan Norbert , Sujith R. I.
Published: July 2024

Phase space reconstruction (PSR) methods allow for the analysis of low-dimensional data with methods from dynamical systems theory, but their application to prediction models, such as those from machine learning (ML), is limited. Therefore, we here present a model adaptive phase space reconstruction (MAPSR) method that unifies the process of PSR with the modeling of the dynamical system. MAPSR is a differentiable PSR based on time-delay embedding and enables ML methods for modeling. The quality of the reconstruction is evaluated by the prediction loss. The discrete-time signal is converted into a continuous-time signal to achieve a loss function, which is differentiable with respect to the embedding delays. The delay vector, which stores all potential embedding delays, is updated along with the trainable parameters of the model to minimize prediction loss. Thus, MAPSR does not rely on any threshold or statistical criterion for determining the dimension and the set of delay values for the embedding process. We apply the MAPSR method to uni- and multivariate time series stemming from chaotic dynamical systems and a turbulent combustor. We find that for the Lorenz system, the model trained with the MAPSR method is able to predict chaotic time series for nearly seven to eight Lyapunov time scales, which is found to be much better compared to other PSR methods [AMI-FNN (average mutual information-false nearest neighbor) and PECUZAL (Pecora-Uzal) methods]. For the univariate time series from the turbulent combustor, the long-term cumulative prediction error of the MAPSR method for the regime of chaos stays between other methods, and for the regime of intermittency, MAPSR outperforms other PSR methods.
Investigation on the intensity contrast of Kα line emission from laser–matter interactions
Authors: Xiao Yangyang , Wang Xiaofang
Published: July 2024

The intensity contrast and its angular distribution of Kα line emission originated from the difference of angular distributions of Kα and bremsstrahlung emissions from copper foil targets bombarded by electrons similar to the hot electrons generated in laser–matter interactions are investigated by Monte Carlo simulations. For mono-energetic electron incidences, a higher contrast Kα emission is generated at large detection angles relative to the incident electron direction and for higher electron energy. The Kα emission contrast is decreased with the increase in target thickness. When the areal density of targets is fixed, the contrast is almost unchanged with the change of target density and thickness. For incident electrons with a Boltzmann energy distribution, a higher contrast Kα emission can also be generated at large detection angles and for higher electron temperatures, but the contrast is lower compared to that for mono-energetic electron incidences, and it is changed only slightly with the increase in target thickness. These results help to understand the contrast of Kα emissions in previous experiments. Suggestions are proposed for future laser–matter interaction experiments for higher contrast Kα emissions.
Active on-site calibration technology of current transformer based on non-rated frequency current injection
Authors: Qi Xin , Wan Baoquan , Zhang Jun , Wang Quan , Chen Haibin , Zhao Qiancheng , Wang Binwu
Published: July 2024

This paper proposes an active on-site calibration method through background current cancellation and non-rated current injection. It can measure the error of the current transformer in service from 1% to 120% rated current percentage without power supply interruption. In order to establish the error relationship between rated frequency and arbitrary frequency, a theoretical analysis of current transformer calibration at the arbitrary frequency has been developed by means of the equivalent circuit. It describes a method to determine the phase angle and ratio errors of the measuring transformers at arbitrary frequencies on the basis of the calibrated error values at rated frequency. To prove the theoretical analysis, an experimental validation was carried out. The experimental results demonstrate that this active onsite calibration is a valid tool for the evaluation of current transformer performances. The calibration results showed that, for both cases (non-rated frequency calibration and mixing frequency calibration), the difference between mean ratio error and rated frequency ratio error was lower than 0.01%, and the difference between mean phase error and rated frequency phase error was lower than 1′, which meets the requirement of the 0.2 accuracy class calibration.
Optical response in a high-TcYBCO nanowire
Authors: Kumar Ankit , Panna Dmitry , Bouscher Shlomi , Kanigel Amit , Hayat Alex
Published: July 2024

We demonstrate the optical response from high-Tc superconductor nanowires at temperatures above that of liquid nitrogen. Using hard oxide Al2O3 as a mask material, we achieved miniaturized YBa2Cu3O7−δ wires with widths nearing 100 nm, a significant milestone for highly sensitive photodetectors. We investigated the photoresponse of these nanowires at temperatures almost an order of magnitude higher than previously reported, under varying temperature and bias current conditions. Our findings reveal a strong correlation between the optical response and the critical parameters of the superconductor, with peak optical responses close to the critical values of temperature and bias current density. Nanowire response to wavelengths from visible to near-infrared range demonstrated a pronounced absorption maximum at temperatures below Tc. These results lay a solid foundation for the development of high-Tc superconductor nanowire single-photon detectors, understanding of nanoscale high-Tc superconductor structure optical behavior, and advancing the prospects of quantum technologies.
Characterization of water propellant in an electron cyclotron resonance thruster
Authors: Sheppard Anna J. , Little Justin M.
Published: July 2024

A coaxial electron cyclotron resonance thruster operating on water vapor propellant is investigated to determine the influence of molecular propellant chemistry on thruster performance. The performance is characterized at different mass flow rates (0.1–0.4 mg/s) and powers (20–200 W) using a thrust stand, ion energy analyzer, and spectrometer. Experimental data are compared to the results from a theoretical model that includes non-equilibrium chemical kinetics. The thruster is observed to transition from a state where power deposition favors propellant dissociation and ionization into a state where it favors electron heating and ion acceleration. The results suggest that the majority of plasma heating occurs in a core region that surrounds the thruster antenna and that propellant flow outside this region is not efficiently utilized for propulsion.
Promoting energy transfer via manipulation of crystallization kinetics of quasi-2D Dion–Jacobson phase perovskites for high-performance green lasers
Authors: Qin Chaochao , Dong Yixiao , Cui Minghuan , Zheng Shuwen , Song Pan , Wang Haiying , Zhang Jicai , Song Jian , Ma Shuhong , Jiao Zhaoyong , Jia Guangrui , Jiang Yuhai , Zhou Zhongpo
Published: July 2024

The quasi-2D Dion–Jacobson perovskite exhibits significant photophysical properties and potential applications. However, the insufficient exciton energy transfer leads to nonradiative recombination that seriously hinders charge transport. Here, an efficient energy transfer is achieved by incorporating the alkali metal, which not only constrains the nucleation of high-n phases and promotes the growth of the middle-n phases but also optimizes the phase distribution and the crystal orientation to promote carrier transport. We achieve a green amplified spontaneous emission with a low threshold of 28.5 μJ/cm2 and a vertical-cavity laser operating in a single-mode configuration with a linewidth of 0.96 nm.
Spin–lattice relaxation with non-linear couplings: Comparison between Fermi’s golden rule and extended dissipaton equation of motion
Authors: Bi Rui-Hao , Su Yu , Wang Yao , Sun Lei , Dou Wenjie
Published: July 2024

Fermi’s golden rule (FGR) offers an empirical framework for understanding the dynamics of spin–lattice relaxation in magnetic molecules, encompassing mechanisms like direct (one-phonon) and Raman (two-phonon) processes. These principles effectively model experimental longitudinal relaxation rates, denoted as T1−1. However, under scenarios of increased coupling strength and nonlinear spin–lattice interactions, FGR’s applicability may diminish. This paper numerically evaluates the exact spin–lattice relaxation rate kernels, employing the extended dissipaton equation of motion formalism. Our calculations reveal that when quadratic spin–lattice coupling is considered, the rate kernels exhibit a free induction decay-like feature, and the damping rates depend on the interaction strength. We observe that the temperature dependence predicted by FGR significantly deviates from the exact results since FGR ignores the higher order effects and the non-Markovian nature of spin–lattice relaxation. Our methods can be easily extended to study other systems with nonlinear spin–lattice interactions and provide valuable insights into the temperature dependence of T1 in molecular qubits when the coupling is strong.
Influence of flow interactions on the aerodynamic characteristics of tandem self-propelled flapping wings with a nonzero angle of attack
Authors: Wang Yi , Wang Zerong , Zhou Chuangxin , Wang Dou
Published: July 2024

It is common in nature for birds or insects to fly in flocks. This study sought to understand the interaction mechanism between complex flows and the aerodynamic characteristics of flocks of flying organisms by employing the lattice-Boltzmann method to investigate tandem self-propelled flapping wings with an angle of attack of 10°. The effects of the initial heaving phase, the initial spacing between the fore and hind wings, and the phase difference between the heaving motions of the fore and hind wings were investigated. It was found that when the fore and hind wings flap in phase, the initial heaving phase and initial spacing can influence the final locomotive state of the tandem system, resulting in three modes: stable flight, collision, and separation. When the tandem system eventually achieves stable flight, only one equilibrium state is observed. In this equilibrium state, the trailing-edge vortex generated by the fore wing reattaches to the lower surface of the hind wing, resulting in 82.3% lower lift efficiency but 19.9% higher propulsive efficiency when compared to a single wing. When the fore and hind wings flap nearly out of phase, the tandem system has better lift characteristics while maintaining good propulsive performance. These findings improve the understanding of the principles of lift and thrust generation in flock flight and will help guide the design of bionic micro air vehicles.
Features of propagation and properties of axially symmetric and azimuthal solitary waves on the curved surface of a half-space cold plasma
Authors: Gradov O. M.
Published: July 2024

The analysis of the behavior features, wave characteristics, and spatial-wave structure of axial-symmetric and azimuthal solitary oscillations at the boundary of a cold semi-infinite plasma is carried out using a closed system of equations describing the interdependence of the curvature of the surface and the properties of the nonlinear surface charge of the plasma. The specificity of the nature of motion, spatial distribution, and interconnection of the parameters of wave formations of each type is described. Numerical calculations have been performed, and an approximate analytical solution has been found.
Symmetry breaking of bound states in the continuum in luminescence response of photonic crystal slabs with embedded Ge nanoislands
Authors: Yurasov Dmitry V. , Dyakov Sergey A. , Smagin Ilia A. , Tikhodeev Sergei G. , Gippius Nikolay A. , Stepikhova Margarita V. , Peretokin Artem V. , Shaleev Mikhail V. , Smagina Zhanna V. , Utkin Dmitry E. , Novikov Alexey V.
Published: July 2024

Bound states in the continuum (BIC) have attracted a great deal of attention in all-dielectric nanophotonics due to their ability to provide spectral features with a very high-quality factor. By definition, BIC cannot be observed in the far field because of the symmetry mismatch with the modes propagating in free space. Despite this, in systems with slightly reduced symmetry, the condition for BIC is lifted, which gives rise to the high-quality resonant features in their optical response. In particular, in photonic crystal slabs, which support the BIC states, the symmetry reduction allows modification of light propagation, reflection, or emission. In this work, using the photonic crystal slabs with embedded Ge nanoislands, we have shown the ability to control their light emission features by symmetry breaking. It was demonstrated that such symmetry breaking due to a change in the basis vectors of the photonic crystal unit cell or a change in the unit cell internal structure could provide independent control knobs to alter the spectral position of photonic crystal modes, their dispersion, and degeneracy. The obtained results reveal additional ways to manage the light emission of active media in photonic crystal slabs.