bluuebunny/crossref_metadata_2025 huggingface dataset:
Prescription opioid dispensing in Canada: an update on recent developments to 2018
Authors: Jones Wayne , Vojtila Lenka , Kurdyak Paul , Fischer Benedikt
Published: October 2020

Canada has been home to comparatively extreme developments in prescription opioid (PO) availability and related harms (e.g. morbidity, mortality) post-2000. Following persistent pan-Canadian increases in PO use, select control measures were implemented and PO dispensing levels—while only inconsistently by province—inverted, and began to plateau or decrease post-2012. We examined annual PO dispensing levels in Canada up until 2018, based on representative prescription sample data from community-based retail pharmacies. Annual prescription-based dispensing data were converted into defined daily doses/1000 population/day by province, and mainly categorized into ‘weak’ and ‘strong’ opioids. All provinces indicated decreasing trends in strong PO levels in most recent years, yet with inter-provincial differences of up to one magnitude in 2018; in about half the provinces, dispensing fell to below-2005 levels. British Columbia had the largest decline in strong PO dispensing from its peak rate (− 48.5%) in 2011. Weak opioid dispensing trends remained more inconsistent and bifurcated across Canada. The distinct effects of individual—including many provincially initiated and governed—PO control measures urgently need to be evaluated. In the meantime, recent reductions in general PO availability across Canada appear to have contributed to shortages in opioid supply for existent, sizable (including non-medical) user populations and may have contributed to recent marked increases in illicit opioid use and harms (including rising deaths).
Textbook-assigned and self-selected topics of Iranian male EFL learners: topic interest, topic familiarity, topic importance, and topic difficulty
Authors: Shakourzadeh Latifeh , Izadpanah Siros
Published: October 2020

In recent years, learner-centered teaching has emphasized the demand for making healthy environment where learners’ preferences, interests, personal experiences, cultural backgrounds and lifestyles are taken into account when making decisions about various characteristics of language learning/teaching The choice of topics, which are used in EFL discussion classes, is considered to play an important role in learners’ propensity to engage in a negotiation for meaning. This study was aimed to investigate the perception of Textbook-Assigned and Self-Selected Topics of Iranian male EFL Learners: topic interest, topic familiarity, topic importance, and topic difficulty based on correlational design. It was carried out with 200 male Intermediate EFL learners who were selected by convenience sampling. Although most teachers might be aware of the importance of a good assessment strategy on the topic interest and topic familiarity, rarely do they use it for topic importance and topic difficulty. The results of the study showed that Iranian male EFL learners mostly preferred the topics to be more interesting and familiar in both textbook-assigned (M = 3.1259, SD = .21553, Sig = .000) and self-selected topics (M = 4.0531, SD = .13334, Sig = .000). In addition, there was a significant difference between the learners’ perceptions of textbook-assigned and self-selected topics in terms of interest and familiarity, but less difference in terms of importance and difficulty. The findings of the study indicated that learners’ selection of their own topics can provide the potential implications for their willingness to participate in second and foreign language learning and take responsibility for their own learning process.
Do journals instruct authors to address sex and gender in psychological science?
Authors: Cavanaugh Courtenay , Abu Hussein Yara
Published: October 2020

Background

Sex and gender influence individuals’ psychology, but are often overlooked in psychological science. The sex and gender equity in research (SAGER) guidelines provide instruction for addressing sex and gender within five sections of a manuscript (i.e., title/abstract, introduction, methods, results, and discussion) (Heidari et al., Res Integr Peer Rev 1:1-9, 2016).

Methods

We examined whether the 89 journals published by the American Psychological Association provide explicit instruction for authors to address sex and gender within these five sections. Both authors reviewed the journal instructions to authors for the words “sex,” and “gender,” and noted explicit instruction pertaining to these five sections.

Results

Only 8 journals (9.0%) instructed authors to address sex/gender within the abstract, introduction, and/or methods sections. No journals instructed authors to address sex and gender in the results or discussion sections.

Conclusion

These journals could increase sex/gender equity and improve the reproducibility of psychological science by instructing authors to follow the SAGER guidelines.
Safeguarding and using global banana diversity: a holistic approach
Authors: Van den houwe Ines , Chase Rachel , Sardos Julie , Ruas Max , Kempenaers Els , Guignon Valentin , Massart Sebastien , Carpentier Sebastien , Panis Bart , Rouard Mathieu , Roux Nicolas
Published: October 2020

The CGIAR genebank International
Musa
Germplasm Transit Centre (ITC) currently holds 1617 banana accessions from 38 countries as an in vitro collection, backed-up by a cryopreserved collection to safeguard global
Musa
diversity in perpetuity. The ITC also serves as a vital safety backup and transit centre for national banana genebanks and ensures that germplasm is clean of pests and diseases and freely available under the International Treaty on Plant Genetic Resources for Food and Agriculture. In more than 35 years of activity, the ITC has distributed over 18,000 banana accession samples to researchers and farmers in 113 countries. Ex situ conservation of vegetatively-propagated crops such as banana poses very particular challenges. Maintaining the ITC genebank is labor intense and costly. Efficiencies are sought through research and development of techniques on detecting viruses, the genetic integrity of accessions, and on innovative means of safeguarding banana diversity, such as conserving populations of wild species by seed banking. Although the conservation of global banana diversity is the main objective of the ITC, significant value comes from its holistic approach to better understand and promote its germplasm through numerous research activities and resources. Techniques for morphological and molecular characterization serve to identify and describe the collection, while also determining what gaps should be filled by collecting missions with national partners. The evaluation of desirable agronomic traits inherent in
Musa
spp. are investigated by a high-throughput phenotyping platform, which helps breeding programs to select cultivars resistant or tolerant to biotic and abiotic stresses. Genomic and bioinformatic studies of several banana wild relatives greatly enhance our understanding of
Musa
genetic diversity, links to important phenotypic traits and bring new methods for management of the collection. Collectively, these research activities produce enormous amounts of data that require curation and dissemination to the public. The two information systems at the ITC,
Musa
Genebank Management System and the
Musa
Germplasm Information System, serve to manage the genebank activities and to make public germplasm-related data for over 30 banana collections worldwide, respectively. By implementing the 10-year workplan set out in the Global Strategy for the Conservation and Use of
Musa
Genetic Resources, the network MusaNet supports
Musa
researchers and stakeholders, including the ITC, and most importantly, links to the world’s banana-producing countries via three regional banana networks.
Delusional infestation: an interface with psychiatry
Authors: Waykar Vijayendra , Wourms Katherine , Tang Michael , Joseph Verghese
Published: October 2020

Delusional infestation (delusional parasitosis) is a relatively rare condition but it has been of interest to a wide range of professionals, including entomologists, zoologists and dermatologists, as patients predominantly seek help from specialties other than psychiatrists. The illness requires a multidisciplinary approach and a strong bond of trust between the treating clinician and the patient to ensure the best possible outcome. This article discusses how clinicians in all specialties should approach patients presenting with the disorder and outlines differential diagnosis and associated laboratory tests. It considers the evidence base for treatment and the success of psychodermatology clinics that provide a ‘neutral setting’ for consultation to address the problem of patients’ non-engagement. Such clinics are few, and there is a need to develop disease-specific pathways in primary care and hospital settings to improve prognosis.
Regeneration in sponge Sycon ciliatum partly mimics postlarval development
Authors: Soubigou Anael , Ross Ethan G. , Touhami Yousef , Chrismas Nathan , Modepalli Vengamanaidu
Published: October 2020

Somatic cells dissociated from an adult sponge can re-organize and develop into a juvenile-like sponge, a remarkable phenomenon of regeneration. However, the extent to which regeneration recapitulates embryonic developmental pathways has remained enigmatic. We have standardized and established a sponge Sycon ciliatum regeneration protocol from dissociated cells. From the morphological analysis, we demonstrated that dissociated sponge cells follow a series of morphological events resembling postembryonic development. We performed high-throughput sequencing on regenerating samples and compared the data with regular postlarval development. Our comparative transcriptomic analysis illuminates that sponge regeneration is equally as dynamic as embryogenesis. We find that sponge regeneration is orchestrated by recruiting pathways like those utilized in embryonic development. We further demonstrated that sponge regeneration is accompanied by cell death at early stages, revealing the importance of apoptosis in remodelling the primmorphs to initiate re-development. Since sponges are likely to be the first branch of extant multicellular animals, we suggest that this system can be explored to study the genetic features underlying the evolution of multicellularity and regeneration.
Epithelial dynamics shed light on mechanisms underlying ear canal defects
Authors: Fons Juan M. , Mozaffari Mona , Malik Dean , Marshall Abigail R. , Connor Steve , Greene Nicholas D. E. , Tucker Abigail S.
Published: October 2020

Defects in ear canal development can cause severe hearing loss as sound waves fail to reach the middle ear. Here we reveal new mechanisms that control human canal development and highlight for the first time the complex system of canal closure and reopening. These processes can be perturbed in mutant mice and in explant culture, mimicking the defects associated with canal aplasia. The more superficial part of the canal forms from an open primary canal that closes and then reopens. In contrast, the deeper part of the canal forms from an extending solid meatal plate that opens later. Closure and fusion of the primary canal was linked to loss of periderm, with failure in periderm formation in Grhl3 mutant mice associated with premature closure of the canal. Conversely, inhibition of cell death in the periderm resulted in an arrest of closure. Once closed, re-opening of the canal occurred in a wave, triggered by terminal differentiation of the epithelium. Understanding these complex processes involved in canal development sheds light on the underlying causes of canal aplasia.
Phosphorylation and dephosphorylation of Ser852 and Ser889 control the clustering, localization and function of PAR3
Authors: Yamashita Kazunari , Mizuno Keiko , Furukawa Kana , Hirose Hiroko , Sakurai Natsuki , Masuda-Hirata Maki , Amano Yoshiko , Hirose Tomonori , Suzuki Atsushi , Ohno Shigeo
Published: October 2020

Cell polarity is essential for various asymmetric cellular events, and the partitioning defective (PAR) protein PAR3 (encoded by PARD3 in mammals) plays a unique role as a cellular landmark to establish polarity. In epithelial cells, PAR3 localizes at the subapical border, such as the tight junction in vertebrates, and functions as an apical determinant. Although we know a great deal about the regulators of PAR3 localization, how PAR3 is concentrated and localized to a specific membrane domain remains an important question to be clarified. In this study, we demonstrate that ASPP2 (also known as TP53BP2), which controls PAR3 localization, links PAR3 and protein phosphatase 1 (PP1). The ASPP2–PP1 complex dephosphorylates a novel phosphorylation site, Ser852, of PAR3. Furthermore, Ser852- or Ser889-unphosphorylatable PAR3 mutants form protein clusters, and ectopically localize to the lateral membrane. Concomitance of clustering and ectopic localization suggests that PAR3 localization is a consequence of local clustering. We also demonstrate that unphosphorylatable forms of PAR3 exhibited a low molecular turnover and failed to coordinate rapid reconstruction of the tight junction, supporting that both the phosphorylated and dephosphorylated states are essential for the functional integrity of PAR3.
Burnout among surgeons; depression, anxiety and stress between consultant versus post-graduate trainee
Authors: Khurshied Saleh , Hisam Aliya , Khurshid Nawal , Khurshid Madiha
Published: October 2020

Objective: To compare depression, anxiety and stress between consultant and post-graduate trainee (PG-trainee) surgeons and to find the difference of different factors i.e. gender, marital status, physical activity, BMI, comorbidity and Income per month between the two.

Methods: A descriptive cross-sectional study of eight months duration from March 2018 to August 2018 was conducted in Military Hospital and Combined Military Hospital, Rawalpindi, Pakistan. Convenient sampling technique was used. DASS 21 questionnaire was used for data collection. Data were entered and analysed by SPSS 22. A p-value of < 0.05 was considered statistically significant.

Results: The mean age of participants was 37.44±10.512 years. Out of 68 participants, 54 (79.4%) were males and 14 (20.6%) were females. There was a significant difference between the consultants and PG trainees in terms of gender, marital status and income per month (p= <0.005) PG-trainees were more depressed and anxious but not stressed as compared to consultants (p= 0.014, 0.012 and 0.280 respectively).

Conclusions: There was a significant association in terms of gender, marital status and income per month between consultants and PG trainees. A statistically significant association was found between consultants and PG trainees concerning depression and anxiety showing PG trainees were more depressed and anxious.

doi: https://doi.org/10.12669/pjms.36.7.1415

How to cite this:Khurshied S, Hisam A, Khurshid N, Khurshid M. Burnout among surgeons; depression, anxiety and stress between consultant versus post-graduate trainee. Pak J Med Sci. 2020;36(7):1745-1748. doi: https://doi.org/

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The evaluation of feeding, mortality and oviposition of poultry red mite (Dermanyssus gallinae) on aging hens using a high welfare on-hen feeding device
Authors: Nunn Francesca , Bartley Kathryn , Palarea-Albaladejo Javier , Nisbet Alasdair J.
Published: October 2020

A study was performed to examine any effect of hen age on the feeding ability and mortality of different life-stages of Dermanyssus gallinae [Poultry Red Mite (PRM)] when fed using a high welfare, on-hen mite feeding device. Mite feeding assays were carried out every two weeks on a cohort of five Lohman Brown hens with devices containing adult and deutonymph PRM or adult and protonymph PRM. Feeding rates and mortality of each PRM life stage and oviposition of adult female PRM were evaluated over an 18-week period. There was a significant reduction in oviposition rates of female PRM as they fed on hens of increasing age. However, no clear trend was detected between the feeding rates of all three haematophagous life stages and hen age. The same conclusion was reached regarding mite mortality post-feeding in both deutonymph and adult female PRMs, although a weak positive association was apparent between hen age and protonymph PRM mortality. This study shows that the on-hen feeding device can be used both for short term studies to assess novel anti-PRM products (new acaricides, vaccines etc.) and longer, longitudinal studies to determine longevity of the effects of such novel anti-PRM products. It also demonstrates that blood feeding by mites on older hens is less able to sustain PRM populations than feeding on younger hens. This on-hen mite feeding device directly impacts upon reduction and refinement by greatly reducing the numbers of birds required per experimental group compared to traditional PRM challenge infestation models and by eliminating the need for birds to be exposed to large numbers of mites for extended periods of time that can cause welfare concerns. This paper describes the methodology for these studies and how to assemble pouches and handle mites both before and after feeding assays.
Ethical conditions for accelerating COVID-19 vaccine research
Authors: Smith Maxwell J. , Emanuel Ezekiel J. , Thomé Beatriz , Upshur Ross E.G.
Published: October 2020

There is a dire need to produce a safe and effective coronavirus disease 2019 (COVID-19) vaccine as quickly as possible to avert an enormous burden of morbidity and mortality. This need for speed has thus far resulted in significant deviations from standard approaches to vaccine research and regulatory approval. Yet, pandemics do not obviate the need for rigorous scientific evaluation of potential interventions and adherence to universal ethical standards. Consequently, steps taken to accelerate clinical research in the context of the current pandemic require an explicit ethical justification, particularly if we expect public trust in the vaccine. We argue that accelerating COVID-19 vaccine research can be ethically justified, but only if social value, scientific validity, and a favourable risk-benefit ratio can be maintained or enhanced when doing so.
Lessons learnt in recruiting schoolchildren into a large asthma case-control study in urban Uganda
Authors: Namutebi Milly , Nnaluwooza Marble , Tumwesige Pius , Mukasa Mike , Apule Barbara , Onen Caroline , Katongole Tonny , Tumusiime Josephine , Akurut Hellen , Elliott Alison , Mpairwe Harriet
Published: October 2020

Schools present an excellent opportunity for research among children and adolescents. We share our experiences and lessons learnt in enrolling schoolchildren into a large asthma case-control study from schools in urban Uganda, and make recommendations for best practices.

Our key lessons were as follows: working closely with the school administration and teachers was vital in gaining timely access to parents of the schoolchildren; having a meeting with parents, within their children’s school premises, was a cost-effective way of reaching a wide audience of potential research participants with our message and an opportunity to seek their participation; allowing flexibility within our processes enabled us to fit our research activities within the school schedule, and with minimal disruptions; however, obtaining informed written consent from parents of children in the boarding section of school remained a challenge.

In conclusion, conducting research in schools in Uganda is feasible and may be a cost-effective way to make the most of limited resources to remedy the research and data deficiencies among school-age children in sub-Saharan Africa.
Can olfactory training support improvement of cognitive functioning in patients with mild cognitive impairment?
Authors: Mydlikowska-Śmigórska Agnieszka , Śmigórski Krzysztof , Szcześniak Dorota , Rymaszewska Joanna
Published: October 2020

Cel pracy

Zgodnie z niektórymi interpretacjami teoretycznymi efektów treningu węchowego, trening ten może pośrednio wpływać pozytywnie na funkcjonowanie poznawcze pacjentów z otępieniem typu alzheimerowskiego. Mechanizm działania w tym wypadku stanowi stymulacja krążenia mózgowego w obszarach mózgu, które są współdzielone przez procesy węchowe i pamięciowe. Celem niniejszego artykułu jest weryfikacja hipotezy, że trening węchowy poprawia funkcjonowanie pamięci i uwagi u pacjentów łagodnymi zaburzeniami poznawczymi.

Metoda

Układ typu „cross-over assignment” został użyty jako metoda interwencji. Uczestnicy z diagnozą łagodnych zaburzeń poznawczych (N=35; 17 mężczyzn i 18 kobiet) stanowili swoją własną grupę kontrolną. Podczas pierwszych 12 tygodni od czasu badania początkowego nie stosowano żadnych oddziaływań terapeutycznych. Pacjenci przeszli kontrolne badania neuropsychologiczne i wkroczyli w drugi etap badania. W tym etapie poddani zostali codziennemu treningowi sprawności węchowej, który obejmował dwie kilkuminutowe sesje dziennie, wykonywane przez następne 3 miesiące. Funkcjonowanie poznawcze pacjentów było mierzone w trzech punktach czasowych: na samym początku, po 3 miesiącach i po 6 miesiącach (od pomiaru początkowego). Użyto następujących skal do pomiaru sprawności pamięci i uwagi: ACE-III, CVLT i MMSE.

Wyniki

Uzyskano istotną statystycznie poprawę funkcjonowania pamięciowego, mierzoną za pomocą CVLT, MMSE, ACE-III: skala pamięci oraz ACE-III: wynik całkowity. Uznaje się je za artefakty związane z efektem uczenia się, nie za prawdziwe efekty treningu. Ponadto stwierdzono poprawę, na poziomie trendu, sprawności funkcjonowania uwagi mierzoną ACE-III: skala uwagi.

Wnioski

Autorzy dyskutują teoretyczne implikacje przeprowadzonego badania. Omawiają metodologiczne wyzwania związane z przyjętym planem badawczym oraz sugerują przyszłe kierunki badań.
Impossibility of Distinguishing Two Preparations for a Pure State from No-signaling
Authors: Pati Arun K.
Published: October 2020

A pure state of a physical system can be prepared in an infinite number of ways. Quantum theory dictates that given a pure state of a physical system it is impossible to distinguish two preparation procedures. Here, we show that the impossibility of distinguishing two preparation procedures for the same pure state follows from the no-signaling principle. Extending this result for a pure bipartite entangled state entails that the impossibility of distinguishing two preparation procedures for a mixed state follows from the impossibility of distinguishing two preparations for a pure bipartite state.Quanta 2020; 9: 16–21.
Early-Stage Venture Incubation and Mentoring Promote Learning, Scaling, and Profitability Among Disadvantaged Entrepreneurs
Authors: Assenova Valentina A.
Published: October 2020

Socially and educationally disadvantaged entrepreneurs often lack the knowledge and prior experience to develop and scale their businesses. Owing to limited educational and employment opportunities, poverty, and discrimination, these entrepreneurs frequently experience low business growth and performance. What factors influence the effectiveness of early-stage venture incubation and mentoring for promoting learning, scaling, and profitability among these entrepreneurs? Two studies in a business incubator serving low-income, underprivileged entrepreneurs in South Africa evaluate this question. Study 1 uses a matched, two-period case-control design to investigate the effects of incubation on business growth by comparing selected and incubated companies to similar also-selected but not incubated ones. The findings show that incubated companies grew 22% more in revenue and 15% more in employment than not incubated companies over the six months between applying to and graduating from the incubator. Study 2 uses instrumental-variable models to evaluate the role that mentoring played in improving business performance by analyzing data from seven cohorts of participants in the incubator randomly assigned to mentors. The findings show that participants assigned to high-ability (versus low-ability) mentors had 3.2% higher revenue and 3.5% higher profits one year after incubation. Further, the benefits of being mentored were more significant for businesses whose entrepreneurs had less pre-entry knowledge and experience, suggesting that mentoring supplemented gaps in human capital. These findings have implications for ways to support disadvantaged entrepreneurs and their businesses through mentoring and early-stage venture incubation.
Coronectomy: not just for Wisdom Teeth
Authors: Owen Brandon , Oliver Graham , Macey-Dare Lucy , Knepil Gregor
Published: October 2020

Coronectomy is most commonly associated with the management of impacted lower third molars where complete removal poses a high risk of inferior alveolar nerve damage. However, coronectomy may be indicated for the management of other teeth with a significant risk of morbidity. A case of a LL6 extended coronectomy is presented. The aim was to prevent inferior alveolar nerve damage, and ensure adequate crown and root removal to facilitate orthodontic alignment of the teeth. Surgery was aided by cone beam CT, and a piezo-surgical technique.

CPD/Clinical Relevance: This case demonstrates the novel application of a coronectomy to manage an infra-occluded lower left first molar, facilitating orthodontic treatment, where complete removal posed a high risk of inferior alveolar nerve damage.
A combined digital-conventional workflow to fabricate a removable partial denture for a patient with a severe gag reflex
Authors: O'Leary Ronan B , Gunderman Anne L
Published: October 2020

Introducing a novel approach to overcoming a profound gag reflex and aversion to conventional dental impression procedures when fabricating a removable partial denture. The digital workflow is becoming increasingly popular in the discipline of fixed prosthodontics. Chairside digitization of a patient's dentition is a less invasive and more comfortable procedure in comparison to conventional dental impression techniques. The advantages can be most relevant to patients with a profound gag-reflex. Currently, certain challenges exist with full digitization in the discipline of removable prosthodontics. Combining digital and conventional workflows may serve as an alternative technique to construct removable prostheses for groups who cannot tolerate conventional methods.

CPD/Clinical Relevance: Many patient groups may not tolerate conventional dental impression techniques. This method offers a combination of existing techniques as a suitable alternative for this cohort.
Less mechanical loading attenuates osteoarthritis by reducing cartilage degeneration, subchondral bone remodelling, secondary inflammation, and activation of NLRP3 inflammasome
Authors: He Zhennian , Nie Pengfei , Lu Jianli , Ling Yong , Guo Jian , Zhang Bin , Hu Jianghua , Liao Jiawei , Gu Jie , Dai Bo , Feng Zhiyun
Published: October 2020

Aims

Osteoarthritis (OA) is a disabling joint disorder and mechanical loading is an important pathogenesis. This study aims to investigate the benefits of less mechanical loading created by intermittent tail suspension for knee OA.

Methods

A post-traumatic OA model was established in 20 rats (12 weeks old, male). Ten rats were treated with less mechanical loading through intermittent tail suspension, while another ten rats were treated with normal mechanical loading. Cartilage damage was determined by gross appearance, Safranin O/Fast Green staining, and immunohistochemistry examinations. Subchondral bone changes were analyzed by micro-CT and tartrate-resistant acid phosphatase (TRAP) staining, and serum inflammatory cytokines were evaluated by enzyme-linked immunosorbent assay (ELISA).

Results

Our radiographs showed that joint space was significantly enlarged in rats with less mechanical loading. Moreover, cartilage destruction was attenuated in the less mechanical loading group with lower histological damage scores, and lower expression of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-5, matrix metalloproteinase (MMP)-3, and MMP-13. In addition, subchondral bone abnormal changes were ameliorated in OA rats with less mechanical loading, as reduced bone mineral density (BMD), bone volume/tissue volume (BV/TV), and number of osteophytes and osteoclasts in the subchondral bone were observed. Finally, the level of serum inflammatory cytokines was significantly downregulated in the less mechanical loading group compared with the normal mechanical loading group, as well as the expression of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3), caspase-1, and interleukin 1β (IL-1β) in the cartilage.

Conclusion

Less mechanical loading alleviates cartilage destruction, subchondral bone changes, and secondary inflammation in OA joints. This study provides fundamental insights into the benefit of non-weight loading rest for patients with OA. Cite this article: Bone Joint Res 2020;9(10):731–741.
Bone mineral as a drug-seeking moiety and a waste dump
Authors: Raina Deepak Bushan , Liu Yang , Jacobson Otto L. P. , Tanner K Elizabeth , Tägil Magnus , Lidgren Lars
Published: October 2020

Bone is a dynamic tissue with a quarter of the trabecular and a fifth of the cortical bone being replaced continuously each year in a complex process that continues throughout an individual’s lifetime. Bone has an important role in homeostasis of minerals with non-stoichiometric hydroxyapatite bone mineral forming the inorganic phase of bone. Due to its crystal structure and chemistry, hydroxyapatite (HA) and related apatites have a remarkable ability to bind molecules. This review article describes the accretion of trace elements in bone mineral giving a historical perspective. Implanted HA particles of synthetic origin have proved to be an efficient recruiting moiety for systemically circulating drugs which can locally biomodulate the material and lead to a therapeutic effect. Bone mineral and apatite however also act as a waste dump for trace elements and drugs, which significantly affects the environment and human health.

Cite this article: Bone Joint Res 2020;9(10):709–718.
Effect of laser cleaning of carbon fiber-reinforced polymer and surface modification on chemical activity and bonding strength
Authors: Tong Yanqun , Chen Xin , Zhang Ang , Fu Yonghong , Ren Xudong , Ye Yunxia , Xin Shanshan
Published: October 2020

Bonding has been used to repair carbon fiber-reinforced polymer (CFRP) materials. However, research has shown that resin residue on the surface of CFRP can cause adhesion problems. Therefore, a reliable surface cleaning procedure is necessary to remove the resin residue before bonding. In this paper, the surface resin was removed by laser cleaning, while the surface properties of CFRP were improved. A pulsed laser cleaning experiment was designed to study the chemical activity and bonding strength of CFRP treated by laser with different laser power and scanning speed. The results showed that as the contact angle of the material surface decreased, chemical activity and adhesive properties were improved. The surface pretreated with laser power of 16 W (scanning speed of 1500 mm/s) had no resin residue and the best adhesive properties; the bonding strength was 1.6 times higher than that of the untreated surface, and the failure mode was dominated by a cohesive damage mode.
SESAM mode-locked Tm:LuYO3 ceramic laser generating 54-fs pulses at 2048  nm
Authors: Zhao Yongguang , Wang Li , Chen Weidong , Pan Zhongben , Wang Yicheng , Liu Peng , Xu Xiaodong , Liu Ying , Shen Deyuan , Zhang Jian , Guina Mircea , Mateos Xavier , Loiko Pavel , Wang Zhengping , Xu Xingguang , Xu Jun , Mero Mark , Griebner Uwe , Petrov Valentin
Published: October 2020

Mode-locked laser operation near 2.05 µm based on a mixed sesquioxide

T
m

:

L
u
Y

O

3

ceramic is demonstrated. Continuous-wave and wavelength-tunable operation is also investigated. Employing a GaSb-based semiconductor saturable absorber mirror as a saturable absorber, a maximum average output power of 133 mW is obtained for a pulse duration of 59 fs. Pulses as short as 54 fs, i.e., eight optical cycles are generated at a repetition rate of

∼

78

M
H
z

with an average output power of 51 mW. To the best of our knowledge, this result represents the shortest pulse duration ever achieved from Tm-based solid-state mode-locked lasers.
High-order mode conversion in a few-mode fiber via laser-inscribed long-period gratings at 1.55  µm and 2  µm wavebands
Authors: Zhao Xinyi , Zhao Yunhe , Liu Yunqi , Liu Zuyao , Mou Chengbo , Shen Lei , Zhang Lei , Luo Jie
Published: October 2020

We demonstrate high-order mode conversion in a few-mode fiber (FMF) via

C
O

2

laser inscribed long-period fiber gratings (LPFGs) at both the 1.55 µm and 2 µm wavebands. At the 1.55 µm waveband, five high-order core modes (the

L
P

11

,

L
P

21

,

L
P

02

,

L
P

31

, and

L
P

12

modes) can be coupled from the

L
P

01

mode with high efficiency by the FMF-LPFGs. The orbital angular momentum beams with different topological charges

(

±
1
,
±
2
,
±
3

)

are experimentally generated by adjusting the polarization controllers. At the 2 µm waveband, three high-order modes (the

L
P

11

,

L
P

21

, and

L
P

02

mode) can be coupled by the FMF-LPFGs with different grating periods. The proposed LPFG-based mode converters could have a potential prospects in mode-division multiplexing and multiwindow broadband optical communication applications.
Capability of physically reasonable OCT-based differentiation between intact brain tissues, human brain gliomas of different WHO grades, and glioma model 101.8 from rats
Authors: Dolganova I. N. , Aleksandrova P. V. , Nikitin P. V. , Alekseeva A. I. , Chernomyrdin N. V. , Musina G. R. , Beshplav S. T. , Reshetov I. V. , Potapov A. A. , Kurlov V. N. , Tuchin V. V. , Zaytsev K. I.
Published: October 2020

Optical coherence tomography (OCT) of the ex vivo rat and human brain tissue samples is performed. The set of samples comprises intact white and gray matter, as well as human brain gliomas of the World Health Organization (WHO) Grades I–IV and glioma model 101.8 from rats. Analysis of OCT signals is aimed at comparing the physically reasonable properties of tissues, and determining the attenuation coefficient, parameter related to effective refractive index, and their standard deviations. Data analysis is based on the linear discriminant analysis and estimation of their dispersion in a four-dimensional principal component space. The results demonstrate the distinct contrast between intact tissues and low-grade gliomas and moderate contrast between intact tissues and high-grade gliomas. Particularly, the mean values of attenuation coefficient are 7.56±0.91, 3.96±0.98, and 5.71±1.49 mm−1 for human white matter, glioma Grade I, and glioblastoma, respectively. The significant variability of optical properties of high Grades and essential differences between rat and human brain tissues are observed. The dispersion of properties enlarges with increase of the glioma WHO Grade, which can be attributed to the growing heterogeneity of pathological brain tissues. The results of this study reveal the advantages and drawbacks of OCT for the intraoperative diagnosis of brain gliomas and compare its abilities separately for different grades of malignancy. The perspective of OCT to differentiate low-grade gliomas is highlighted by the low performance of the existing intraoperational methods and instruments.
High-performance imaging of cell-substrate contacts using refractive index quantification microscopy
Authors: Xin Ziqiang , Zhang Chonglei , Sun Lixun , Wan Chao , Chen Ting , Chen Houkai , Wang Min , Wang Yijia , Zhu Siwei , Yuan Xiaocong
Published: October 2020

Non-invasive imaging of living cells is an advanced technique that is widely used in the life sciences and medical research. We demonstrate a refractive index quantification microscopy (RIQM) that enables label-free studies of glioma cell-substrate contacts involving cell adhesion molecules and the extracellular matrix. This microscopy takes advantage of the smallest available spot created when an azimuthally polarized perfect optical vortex beam (POV) is tightly focused with a first-order spiral phase, which results in a relatively high imaging resolution among biosensors. A high refractive index (RI) resolution enables the RI distribution within neuronal cells to be monitored. The microscopy shows excellent capability for recognizing cellular structures and activities, demonstrating great potential in biological sensing and live-cell kinetic imaging.
Manipulating the light-matter interaction in a topological photonic crystal heterostructure
Authors: Ming Qing Ye , Feng Ma Hui , Wei Wu Liang , Jun Cui Tie
Published: October 2020

We theoretically and numerically investigate the ligh-matter interaction in a classic topological photonic crystal (PhC) heterostructure, which consists of two opposite-facing 4-period PhCs spaced by a dielectric layer. Due to the excitation of topological edge mode (TEM) at the interface of the two PhCs, the strong coupling between incident light and TEM produces a high quality resonance peak, which can be applied to many optical devices. As a refractive index sensor, it achieves a sensitivity of 254.5 nm/RIU and a high figure of merit (> 250), which is superior to many previously reported sensors. We further study the coupling between photons and excitons by replacing the pure dielectric layer with the J-aggregates doped layer. By tuning the thickness of the doped layer and the angle of incident light, the dispersive TEM can efficiently interact with the molecular excitons to form a hybrid mode with TEM-like or exciton-like components, showing interesting energy transfer characteristics and flexible modulation characteristics. This work may be helpful for a better understanding of light-matter interactions in a topological PhC heterostructure, and achieve potential applications in related optical devices.
All-optical phase-sensitive detection for ultra-fast quantum computation
Authors: Takanashi Naoto , Inoue Asuka , Kashiwazaki Takahiro , Kazama Takushi , Enbutsu Koji , Kasahara Ryoichi , Umeki Takeshi , Furusawa Akira
Published: October 2020

Phase-sensitive detection is the essential projective measurement for measurement-based continuous-variable quantum information processing. The bandwidth of conventional electrical phase-sensitive detectors is up to several gigahertz, which would limit the speed of quantum computation. It is theoretically proposed to realize terahertz-order detection bandwidth by using all-optical phase-sensitive detection with an optical parametric amplifier (OPA). However, there have been experimental obstacles to achieve large parametric gain for continuous waves, which is required for use in quantum computation. Here, we adopt a fiber-coupled χ(2) OPA made of a periodically poled LiNbO3 waveguide with high durability for intense continuous-wave pump light. Thanks to that, we manage to detect quadrature amplitudes of broadband continuous-wave squeezed light. 3 dB of squeezing is measured up to 3 THz of sideband frequency with an optical spectrum analyzer. Furthermore, we demonstrate the phase-locking and dispersion compensation of the broadband continuous-wave squeezed light, so that the phase of the squeezed light is maintained over 1 THz. The ultra-broadband continuous-wave detection method and dispersion compensation would help to realize all-optical quantum computation with over-THz clock frequency.
Sensitivity enhancement through RIN suppression in dual-polarization fiber optic gyroscopes for rotational seismology
Authors: He Dong , Cao Yuwen , Zhou Tong , Peng Chao , Li Zhengbin
Published: October 2020

Portable sensors with a sufficiently high sensitivity in detecting small rotational motions have attracted significant attention in the field of rotational seismology. In this study, we propose and demonstrate a dual-polarization fiber optic gyroscope (IFOG) with a portable-sized fiber coil. Excess relative intensity noise (RIN) is effectively compensated for owing to the opposite parities and strong correlation of the two orthogonal polarized light, whereas other noises including coherent phase noise and thermal phase noise have also been handled well. In a test on detecting the rotation rate of the Earth, an enhanced sensitivity of

20

n
r
a
d

/

s

/

H
z

over a frequency range of 0.01 Hz to 30 Hz was demonstrated using the proposed design with an enclosed area of only 68 m2.
Integrated optical isolators using electrically driven acoustic waves
Authors: Dostart Nathan , Ehrlichman Yossef , Gentry Cale , Popović Miloš A.
Published: October 2020

We propose and investigate the performance of integrated photonic isolators based on non-reciprocal mode conversion facilitated by unidirectional, traveling acoustic waves. A triply-guided waveguide system on-chip, comprising two optical modes and an electrically-driven acoustic mode, facilitates the non-reciprocal mode conversion and is combined with spatial mode filters to create the isolator. The co-guided and co-traveling arrangement enables isolation with no additional optical loss, without magnetic-optic materials, and with low power consumption. The approach is theoretically evaluated with simulations predicting over 20 dB of isolation and 2.6 dB of insertion loss with a 370 GHz optical bandwidth and 1 cm device length. The isolator uses only 1 mW of electrical drive power, an improvement of 1–3 orders of magnitude over the state of the art. The electronic drive and lack of magneto-optic materials suggest the potential for straightforward integration with drive circuits, including in monolithic CMOS electronic-photonic platforms, enabling a fully contained ‘black box’ optical isolator with two optical ports and DC electrical power.
Thermal tuning of arsenic selenide glass thin films and devices
Authors: Frantz Jesse A. , Clabeau Anthony , Myers Jason D. , Bekele Robel Y. , Nguyen Vinh Q. , Sanghera Jasbinder S.
Published: October 2020

We present a method of post-deposition tuning of the optical properties of thin film dielectric filters and mirrors containing chalcogenide glass (ChG) layers by thermally adjusting their refractive index. A common challenge associated with the use of ChG films in practical applications is that they suffer from slight run-to-run variations in optical properties resulting from hard-to-control changes in source material and deposition conditions. These variations lead to inconsistencies in optical constants, making the fabrication of devices with prescribed optical properties challenging. In this paper, we present new work that takes advantage of the large variation of a ChG films’ refractive index as a function of annealing. We have carried out extensive characterization of the thermal index tuning and thickness change of arsenic selenide (As2Se3) ChG thin films and observed refractive index changes larger than 0.1 in some cases. We show results for refractive index as a function of annealing time and temperature and propose a model to describe this behavior based on bond rearrangement. We apply thermal refractive index tuning to permanently shift the resonance of a Fabry-Perot filter and the cutoff wavelength of a Bragg reflector. The Bragg reflector, consisting of alternating As2Se3 and CaF2 layers, exhibits high reflectance across a ∼550 nm band with only five layers. Modeling results are compared with spectroscopic measurements, demonstrating good agreement.
Trade-offs in absorption and scattering by nanophotonic structures
Authors: Schab Kurt , Rothschild Austin , Nguyen Kristi , Capek Miloslav , Jelinek Lukas , Gustafsson Mats
Published: October 2020

Trade-offs between absorption and scattering cross sections of lossy obstacles confined to an arbitrarily shaped volume are formulated as a multi-objective optimization problem solvable by Lagrangian-dual methods. Solutions to this optimization problem yield a Pareto-optimal set, the shape of which reveals the feasibility of achieving simultaneously extremal absorption and scattering. Two forms of the trade-off problems are considered involving both pre-assigned loss and reactive material parameters. Numerical comparisons between the derived multi-objective bounds and several classes of realized structures are made. Additionally, low-frequency (electrically small, long wavelength) limits are examined for certain special cases.
Strong exciton–plasmon coupling in dye-doped film on a planar hyperbolic metamaterial
Authors: Tanyi E. K. , Hong N. , Sawyer T. , Van Schenck J. D. B. , Giesbers G. , Ostroverkhova O. , Cheng L.-J.
Published: October 2020

We experimentally demonstrate the direct strong coupling between the

S
0

→

S
1

absorption transition of rhodamine 6G (R6G) dye molecules and the surface plasmon polaritons of a hyperbolic metamaterial (HMM) substrate. The surface plasmon mode was excited by a guided mode of the R6G-doped polymer thin film on the HMM. The coupling strengths of the interactions between the surface plasmon and two molecular exciton modes are greater than the average linewidths of the individual modes indicating a strong coupling regime. This is the first, to the best of our knowledge, experimental demonstration of the direct strong coupling between the resonance mode supported by the HMM and the dye molecules on the HMM surface, not embedded in the HMM structure. The study may provide the foundation for the development of novel planar photonic or electronic devices.
Silicon-microring-based interrogator for TDM-FBG sensors enabled by pulse compression
Authors: Yang Fan , Zhang Wenjia , Liu Qingwen , He Zuyuan
Published: October 2020

We propose a silicon microring resonator (MRR)-based high-resolution interrogator enabled by novel slope-assisted filtering and pulse compression technology for time division multiplexed fiber Bragg grating (TDM-FBG) sensors. Golay coded optical pulses are launched into an FBG sensor array to produce a series of reflected pulses with different time delays due to various transmission distances. A tunable MRR filter is used for interrogation of all FBG sensors by direct detection and subsequent signal processing. As a proof of concept, a strain sensing experiment is conducted using a

2
×
1

TDM-FBG sensor array. The performance of the proposed interrogation system is evaluated experimentally, and the dynamic strain resolution can be as high as

20

n
ε

/

H
z

.
Single-walled carbon-nanotube saturable absorber assisted Kerr-lens mode-locked Tm:MgWO4 laser
Authors: Wang Li , Chen Weidong , Zhao Yongguang , Wang Yicheng , Pan Zhongben , Lin Haifeng , Zhang Ge , Zhang Lizhen , Lin Zhoubin , Bae Ji Eun , Park Tae Gwan , Rotermund Fabian , Loiko Pavel , Mateos Xavier , Mero Mark , Griebner Uwe , Petrov Valentin
Published: October 2020

We demonstrate sub-100-fs Kerr-lens mode-locking of a

T
m

:

M
g
W

O

4

laser emitting at

∼

2

µ

m

assisted by a single-walled carbon-nanotube saturable absorber. A maximum average output power of 100 mW is achieved with pulse duration of 89 fs at a pulse repetition rate of

∼

86

M
H
z

. The shortest pulse duration derived from frequency-resolved optical gating amounts to 76 fs at 2037 nm, corresponding to nearly bandwidth-limited pulses. To the best of our knowledge, these are the shortest pulses generated from any Tm-doped tungstate crystal and the first report on saturable absorber assisted Kerr-lens mode-locking of a Tm laser at

∼

2

µ

m

.