Observation of room-temperature polar skyrmions.

Complex topological configurations are fertile ground for exploring emergent phenomena and exotic phases in condensed-matter physics. For example, the recent discovery of polarization vortices and their associated complex-phase coexistence and response under applied electric fields in superlattices of (PbTiO3)n/(SrTiO3)n suggests the presence of a complex, multi-dimensional system capable of interesting physical responses, such as chirality, negative capacitance and large piezo-electric responses1-3. Here, by varying epitaxial constraints, we discover room-temperature polar-skyrmion bubbles in a lead titanate layer confined by strontium titanate layers, which are imaged by atomic-resolution scanning transmission electron microscopy. Phase-field modelling and second-principles calculations reveal that the polar-skyrmion bubbles have a skyrmion number of +1, and resonant soft-X-ray diffraction experiments show circular dichroism, confirming chirality. Such nanometre-scale polar-skyrmion bubbles are the electric analogues of magnetic skyrmions, and could contribute to the advancement of ferroelectrics towards functionalities incorporating emergent chirality and electrically controllable negative capacitance.

COVID-19 Induces Neuroinflammation and Suppresses Peroxisomes in the Brain.

OBJECTIVE: Peroxisome injury occurs in the central nervous system (CNS) during multiple virus infections that result in neurological disabilities. We investigated host neuroimmune responses and peroxisome biogenesis factors during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using a multiplatform strategy. METHODS: Brain tissues from coronavirus disease 2019 (COVID-19) (n = 12) and other disease control (ODC) (n = 12) patients, as well as primary human neural cells and Syrian hamsters, infected with a clinical variant of SARS-CoV-2, were investigated by droplet digital polymerase chain reaction (ddPCR), quantitative reverse transcriptase PCR (RT-qPCR), and immunodetection methods. RESULTS: SARS-CoV-2 RNA was detected in the CNS of 4 patients with COVID-19 with viral protein (NSP3 and spike) immunodetection in the brainstem. Olfactory bulb, brainstem, and cerebrum from patients with COVID-19 showed induction of pro-inflammatory transcripts (IL8, IL18, CXCL10, NOD2) and cytokines (GM-CSF and IL-18) compared to CNS tissues from ODC patients (p < 0.05). Peroxisome biogenesis factor transcripts (PEX3, PEX5L, PEX11ß, and PEX14) and proteins (PEX3, PEX14, PMP70) were suppressed in the CNS of COVID-19 compared to ODC patients (p < 0.05). SARS-CoV-2 infection of hamsters revealed viral RNA detection in the olfactory bulb at days 4 and 7 post-infection while inflammatory gene expression was upregulated in the cerebrum of infected animals by day 14 post-infection (p < 0.05). Pex3 transcript levels together with catalase and PMP70 immunoreactivity were suppressed in the cerebrum of SARS-CoV-2 infected animals (p < 0.05). INTERPRETATION: COVID-19 induced sustained neuroinflammatory responses with peroxisome biogenesis factor suppression despite limited brainstem SARS-CoV-2 neurotropism in humans. These observations offer insights into developing biomarkers and therapies, while also implicating persistent peroxisome dysfunction as a contributor to the neurological post-acute sequelae of COVID-19. ANN NEUROL 2023;94:531-546.

Probiotic potential of a novel endophytic Streptomyces griseorubens CIBA-NS1 isolated from Salicornia sp. against Vibrio campbellii infection in shrimp.

A novel endophytic Streptomyces griseorubens CIBA-NS1 was isolated from a salt marsh plant Salicornia sp. The antagonistic effect of S. griseorubens against Vibrio campbellii, was studied both in vitro and in vivo. The strain was validated for its endophytic nature and characterized through scanning electron microscopy, morphological and biochemical studies and 16SrDNA sequencing. The salinity tolerance experiment has shown that highest antibacterial activity was at 40‰ (16 ± 1.4 mm) and lowest was at 10 ‰ salinity (6.94 ± 0.51 mm). In vivo exclusion of Vibrio by S. griseorubens CIBA-NS1 was studied in Penaeus indicus post larvae and evaluated for its ability to improve growth and survival of P. indicus. After 20 days administration of S. griseorubens CIBA-NS1, shrimps were challenged with V. campbellii. The S. griseorubens CIBA-NS1 reduced Vibrio population in test group when compared to control, improved survival (60.5 ± 6.4%) and growth, as indicated by weight gain (1.8 ± 0.05g). In control group survival and growth were 48.4 ± 3.5% and 1.4 ± 0.03 g respectively. On challenge with V. campbellii, the S. griseorubens CIBA-NS1 administered group showed better survival (85.6 ± 10%) than positive control (64.3 ± 10%). The results suggested that S. griseorubens CIBA-NS1 is antagonistic to V. campbellii, reduce Vibrio population in the culture system and improve growth and survival. This is the first report on antagonistic activity of S. griseorubens isolated from salt marsh plant Salicornia sp, as a probiotic candidate to prevent V. campbellii infection in shrimps.

Search for Baryon-Number-Violating Processes in B

We report the results of the first search for B^{-} decays to the Ξ[over ¯]_{c}^{0}Λ[over ¯]_{c}^{-} final state using 711 fb^{-1} of data collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The results are interpreted in terms of both direct baryon-number-violating B^{-} decay and Ξ_{c}^{0}-Ξ[over ¯]_{c}^{0} oscillations which follow the standard model decay B^{-}→Ξ_{c}^{0}Λ[over ¯]_{c}^{-}. We observe no evidence for baryon number violation and set the 95% confidence-level upper limits on the ratio of baryon-number-violating and standard model branching fractions B(B^{-}→Ξ[over ¯]_{c}^{0}Λ[over ¯]_{c}^{-})/B(B^{-}→Ξ_{c}^{0}Λ[over ¯]_{c}^{-}) to be <2.7% and on the effective angular frequency of mixing ω in Ξ_{c}^{0}-Ξ[over ¯]_{c}^{0} oscillations to be <0.76 ps^{-1} (equivalent to τ_{mix}>1.3 ps).

Measurements of the Branching Fraction, Polarization, and CP Asymmetry for the Decay B

We present a comprehensive study of B^{0}→ωω decays using 772×10^{6} BB[over ¯] pairs collected with the Belle detector at the KEKB e^{+}e^{-} collider. This process is a suppressed charmless decay into two vector mesons and can exhibit interesting polarization and CP violation. The decay is observed for the first time with a significance of 7.9 standard deviations. We measure a branching fraction B=(1.53±0.29±0.17)×10^{-6}, a fraction of longitudinal polarization f_{L}=0.87±0.13±0.13, and a time-integrated CP asymmetry A_{CP}=-0.44±0.43±0.11, where the first uncertainties listed are statistical and the second are systematic. This is the first observation of B^{0}→ωω and the first measurements of f_{L} and A_{CP} for this decay.

Measurement of Angular Coefficients of B[over ¯]→D

We measure the complete set of angular coefficients J_{i} for exclusive B[over ¯]→D^{*}ℓν[over ¯]_{ℓ} decays (ℓ=e, µ). Our analysis uses the full 711 fb^{-1} Belle dataset with hadronic tag-side reconstruction. The results allow us to extract the form factors describing the B[over ¯]→D^{*} transition and the Cabibbo-Kobayashi-Maskawa matrix element |V_{cb}|. Using recent lattice QCD calculations for the hadronic form factors, we find |V_{cb}|=(40.7±0.7)×10^{-3} using the Boyd-Grinstein-Lebed parametrization, compatible with determinations from inclusive semileptonic decays. We search for lepton flavor universality violation as a function of the hadronic recoil parameter w and investigate the differences of the electron and muon angular distributions. We find no deviation from standard model expectations.

Primary preputial reconstruction following surgical excision of cutaneous mast cell tumours without penile amputation in eight dogs.

CASE HISTORY: Medical records from a single referral hospital (Davies Veterinary Specialists, Hitchin, UK) were reviewed to identify dogs (n = 8) with preputial cutaneous mast cell tumours (CMCT) that underwent surgical excision and primary preputial reconstruction, preserving the penis and urethra, after clients declined alternatives such as penile amputation and urethrostomy, from June 2017-June 2022. CLINICAL FINDINGS: Tumours had a median diameter of 21.5 (min 15, max 30) mm, were located cranioventrally (3/8), caudoventrally (1/8), laterally (2/8) and dorsally (2/8) relative to the prepuce and were diagnosed as CMCT based on cytology. No dogs had hepatic or splenic metastasis on cytology but inguinal lymph node metastasis was identified in 3/4 dogs sampled. TREATMENT AND OUTCOME: The owners of all dogs had declined penile amputation and scrotal urethrostomy. The CMCT were excised and primary reconstruction of the prepuce performed. Surgical lateral margins of 10, 20 or 30 mm were used and the deep margin excised the inner preputial lamina or underlying muscular fascia. The deep margin for caudoventral CMCT involved excision of the underlying SC adipose tissue. Preputial advancement was performed in 3/8 dogs to achieve adequate penile coverage. Histopathology confirmed all CMCT were Kiupel low grade, Patnaik grade II with complete margins in 6/8 dogs but identified metastasis only in one inguinal lymph node from one dog. Two dogs encountered minor complications (infection and a minor dehiscence) and one dog had a major complication (infection with major dehiscence). Median follow-up duration was 125 weeks, excluding one dog with 4 weeks of follow-up. None of the dogs experienced local recurrence or died of mast cell disease during the available follow-up period. CLINICAL RELEVANCE:  This clinical study evaluated a surgical alternative to penile amputation and advanced reconstructive techniques for Kuipel low/Patnaik grade II preputial CMCT when these procedures were declined by owners. Surgical excision of preputial CMCT with lateral margins of 10, 20 or 30 mm with primary preputial reconstruction is achievable with low morbidity and a good outcome when penile amputation and scrotal urethrostomy is not an option.

Three Years of Experience of ENT-Head and Neck Trauma in a Tertiary Care Centre of Nepal.

Background Trauma to ENT-Head and Neck region is one of the commonest emergencies. The neck and face being exposed parts of our body are vulnerable to traumatic injuries. Objective To study epidemiological pattern, site, mode and cause of trauma in ENT Head and Neck region, their management and outcome. Method This retrospective study was conducted in the department of ENT-Head and Neck Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal. Medical records of the patients admitted with Head and Neck trauma from April 14, 2019 to April 13, 2022 were retrieved from the Medical Records Section and reviewed. Trauma cases which were managed on an OPD basis and those patients with incomplete data and polytrauma were excluded. Result Most of the trauma cases were in the adults 139 (72.41%). Males were more common than females (80.73%). Oral cavity and oropharyngeal injury 37 (69.81%) was most common in the pediatric patients. In adults nose and facial trauma79 (56.83%) was the most common site of injury. Fall was the most common mode of injury in pediatric patients 36 (67.92%) while in adults it was interpersonal violence 43 (30.94%). Conclusion ENT-Head and Neck trauma was more commonly observed in male adults. Paediatric patients were found to be vulnerable to fall while in adults interpersonal violence was the most common mode of trauma. Oral cavity and oro-pharynx were the most common sites of injury in children while nose and facial trauma were the most common in adults. There were no significant complications and mortality reported during the hospital stay.

Search for the Lepton Flavor Violating Decays B

We present a search for the lepton flavor violating decays B^{+}→K^{+}τ^{±}ℓ^{∓}, with ℓ=(e,µ), using the full data sample of 772×10^{6} BB[over ¯] pairs recorded by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We use events in which one B meson is fully reconstructed in a hadronic decay mode. We find no evidence for B^{±}→K^{±}τℓ decays and set upper limits on their branching fractions at the 90% confidence level in the (1-3)×10^{-5} range. The obtained limits are the world's best results.

First Measurement of the Michel Parameter ξ

We report the first measurement of the Michel parameter ξ^{'} in the τ^{-}→µ^{-}ν[over ¯]_{µ}ν_{τ} decay with a new method proposed just recently. The measurement is based on the reconstruction of the τ^{-}→µ^{-}ν[over ¯]_{µ}ν_{τ} events with subsequent muon decay in flight in the Belle central drift chamber. The analyzed data sample of 988 fb^{-1} collected by the Belle detector corresponds to approximately 912×10^{6} τ^{+}τ^{-} pairs. We measure ξ^{'}=0.22±0.94(stat)±0.42(syst), which is in agreement with the standard model prediction of ξ^{'}=1. Statistical uncertainty dominates in this study, being a limiting factor, while systematic uncertainty is well under control. Our analysis proved the practicability of this promising method and its prospects for further precise measurement in future experiments.

Evidence of a New Excited Charmed Baryon Decaying to Σ_{c}(2455)

We present the study of B[over ¯]^{0}→Σ_{c}(2455)^{0,++}π^{±}p[over ¯] decays based on 772×10^{6} BB[over ¯] events collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The Σ_{c}(2455)^{0,++} candidates are reconstructed via their decay to Λ_{c}^{+}π^{∓} and Λ_{c}^{+} decays to pK^{-}π^{+}, pK_{S}^{0}, and Λπ^{+} final states. The corresponding branching fractions are measured to be B(B[over ¯]^{0}→Σ_{c}(2455)^{0}π^{+}p[over ¯])=(1.09±0.06±0.07)×10^{-4} and B(B[over ¯]^{0}→Σ_{c}(2455)^{++}π^{-}p[over ¯])=(1.84±0.11±0.12)×10^{-4}, which are consistent with the world average values with improved precision. A new structure is found in the M_{Σ_{c}(2455)^{0,++}π^{±}} spectrum with a significance of 4.2σ including systematic uncertainty. The structure is possibly an excited Λ_{c}^{+} and is tentatively named Λ_{c}(2910)^{+}. Its mass and width are measured to be (2913.8±5.6±3.8) MeV/c^{2} and (51.8±20.0±18.8) MeV, respectively. The products of branching fractions for the Λ_{c}(2910)^{+} are measured to be B(B[over ¯]^{0}→Λ_{c}(2910)^{+}p[over ¯])×B(Λ_{c}(2910)^{+}→Σ_{c}(2455)^{0}π^{+})=(9.5±3.6±1.6)×10^{-6} and B(B[over ¯]^{0}→Λ_{c}(2910)^{+}p[over ¯])×B(Λ_{c}(2910)^{+}→Σ_{c}(2455)^{++}π^{-})=(1.24±0.35±0.10)×10^{-5}. Here, the first and second uncertainties are statistical and systematic, respectively.

First Observation of Λπ

Using the data sample of 980 fb^{-1} collected with the Belle detector operating at the KEKB asymmetric-energy e^{+}e^{-} collider, we present the results of an investigation of the Λπ^{+} and Λπ^{-} invariant mass distributions looking for substructure in the decay Λ_{c}^{+}→Λπ^{+}π^{+}π^{-}. We find a significant signal in each mass distribution. When interpreted as resonances, we find for the Λπ^{+} (Λπ^{-}) combination a mass of 1434.3±0.6(stat)±0.9(syst) MeV/c^{2} [1438.5±0.9(stat)±2.5(syst) MeV/c^{2}], an intrinsic width of 11.5±2.8(stat)±5.3(syst) MeV/c^{2} [33.0±7.5(stat)±23.6(syst) MeV/c^{2}] with a significance of 7.5σ (6.2σ). As these two signals are very close to the K[over ¯]N threshold, we also investigate the possibility of a K[over ¯]N cusp, and find that we cannot discriminate between these two interpretations due to the limited size of the data sample.

First Measurement of the Nuclear-Recoil Ionization Yield in Silicon at 100 eV.

We measured the nuclear-recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a monoenergetic beam scatter off of the silicon nuclei at angles corresponding to energy depositions from 4 keV down to 100 eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100 eV. These results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale.

First Simultaneous Determination of Inclusive and Exclusive |V_{ub}|.

The first simultaneous determination of the absolute value of the Cabibbo-Kobayashi-Maskawa matrix element V_{ub} using inclusive and exclusive decays is performed with the full Belle data set at the ϒ(4S) resonance, corresponding to an integrated luminosity of 711 fb^{-1}. We analyze collision events in which one B meson is fully reconstructed in hadronic modes. This allows for the reconstruction of the hadronic X_{u} system of the semileptonic b→uℓν[over ¯]_{ℓ} decay. We separate exclusive B→πℓν[over ¯]_{ℓ} decays from other inclusive B→X_{u}ℓν[over ¯]_{ℓ} and backgrounds with a two-dimensional fit that utilizes the number of charged pions in the X_{u} system and the four-momentum transfer q^{2} between the B and X_{u} systems. Combining our measurement with information from lattice QCD and QCD calculations of the inclusive partial rate as well as external experimental information on the shape of the B→πℓν[over ¯]_{ℓ} form factor, we determine |V_{ub}^{excl}|=(3.78±0.23±0.16±0.14)×10^{-3} and |V_{ub}^{incl}|=(3.88±0.20±0.31±0.09)×10^{-3}, respectively, with the uncertainties being the statistical error, systematic errors, and theory errors. The ratio of |V_{ub}^{excl}|/|V_{ub}^{incl}|=0.97±0.12 is compatible with unity.

Search for a Heavy Neutrino in τ Decays at Belle.

We report on a search for a heavy Majorana neutrino in the decays τ^{-}→π^{-}ν_{h}, ν_{h}→π^{±}ℓ^{∓}, ℓ=e, µ. The results are obtained using the full data sample of 988 fb^{-1} collected with the Belle detector at the KEKB asymmetric energy e^{+}e^{-} collider, which contains 912×10^{6} ττ pairs. We observe no significant signal and set 95% CL upper limits on the couplings of the heavy right-handed neutrinos to the conventional standard model left-handed neutrinos in the mass range 0.2-1.6 GeV/c^{2}. This is the first study of a mixed couplings of heavy neutrinos to τ leptons and light-flavor leptons.

First Measurement of the B

We study B^{+}→π^{+}π^{0}π^{0} using 711 fb^{-1} of data collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We measure an inclusive branching fraction of (19.0±1.5±1.4)×10^{-6} and an inclusive CP asymmetry of (9.2±6.8±0.7)%, where the first uncertainties are statistical and the second are systematic, and a B^{+}→ρ(770)^{+}π^{0} branching fraction of (11.2±1.1±0.9_{-1.6}^{+0.8})×10^{-6}, where the third uncertainty is due to possible interference with B^{+}→ρ(1450)^{+}π^{0}. We present the first observation of a structure around 1 GeV/c^{2} in the π^{0}π^{0} mass spectrum, with a significance of 6.4σ, and measure a branching fraction to be (6.9±0.9±0.6)×10^{-6}. We also report a measurement of local CP asymmetry in this structure.

Are the Cytotoxic Properties of Conjugated Unsaturated Ketones Inactivated by Thiols?

The focus of this study was to examine whether the conversion of cytotoxic conjugated unsaturated ketones (or enones) into the corresponding thiol adducts leads to a reduction or abolition of cytotoxic potencies. A number of enones and related thiol adducts were evaluated against human HCT116 and HT29 colon cancer cells. Some 63% of the IC50 values are less than 10 µM and several compounds are more toxic than 5-FU. The thiol adducts are either more potent or are equipotent with the corresponding enones. A number of compounds are far more toxic to HCT116 and HT29 neoplasms than non-malignant CRL1790 cells leading to impressive Selectivity Index figures. An additional positive feature of these compounds is that they have favorable ADME properties.

Evaluation of transfer factors of 226Ra, 232Th, and 40K radionuclides from soil to grass and mango in the northern region of Bangladesh.

Bangladesh is a rapidly developing country, which is vulnerable to various types of pollution due to the large-scale industrial and associated human activities that might potentially affect the locally harvested foodstuffs. Therefore, the transfer factor is an essential tool to assess the safety of foodstuffs due to the presence of natural radioactivity in environmental matrix and/or strata. This is a first study of its kind conducted in a well-known region for mango farming in Bangladesh, measuring the uptake of naturally occurring radioactive materials (NORMs) by grass and mango from soil to assess the ingestion doses to humans. The HPGe gamma-ray detector was used to determine the concentrations of NORMs in samples of soil (20), grass (10), and mango (10), which were then used to calculate the transfer factors of soil to grass and soil to mango. Average activity concentrations of 226Ra, 232Th, and 40K in associated soil samples (47.27 ± 4.10, 64.49 ± 4.32, 421.60 ± 28.85) of mango and 226Ra and 232Th in associated soil samples (45.07 ± 3.93, 52.17 ± 3.95) of grass were found to exceed the world average values. The average transfer factors (TFs) for mango were obtained in the order of 40K(0.80) > 226Ra (0.61) > 232Th (0.31), and for grass, it shows the order of 40K (0.78) > 232Th (0.64) > 226Ra (0.56). However, a few values (3 mango samples and 3 grass samples) of the estimated TFs exceeded the recommended limits. Moreover, Bangladesh lacks the transfer factors for most of the food crops; therefore, calculation of TFs in the major agricultural products is required all over Bangladesh, especially the foodstuffs produced near the Rooppur Nuclear Power Plant, which is scheduled to be commissioned in 2023.

Antibacterial effect of kitchen herbs against pathogenic multidrug-resistant E. coli isolates from calf diarrhoea.

Calf diarrhoea remains the biggest challenge both in the small and large farms. Infectious diarrhoea is associated with many pathogens, Escherichia coli being one, but majority are systematically treated with antibiotics. Since antimicrobial resistance (AMR) is a growing menace, the need to find alternative prophylactic solutions using popular kitchen herbs such as Trachyspermum ammi (carom seeds), Curcuma longa (turmeric) and cinnamon (Cinnamomum sp.) extracts is been investigated against virulent form of E. coli isolated from calf diarrhoea. The virulence factors identified in these isolates were ST (32.5%), LT (20%), eaeA (15%), stx1 (2.5%) and stx2 (5%) with the occurrence of the most common serogroups as O18 (15%) followed by O111 (12.5%). Highest resistance was seen with beta lactam + beta lactamase inhibitor (amoxicillin/clavulanic acid) followed by beta lactams (ampicillin, cefuroxime and cefepime). The zone of inhibition due to cinnamon (methanol) and carom seed (ethanol) extracts (500 to 250 µg/mL concentration) on E. coli bacteria was >19 mm, respectively. Turmeric, cinnamon and carom had the potency of inhibiting the pathogenic E. coli which maybe suggestive of its use in calf diets as prophylaxis against diarrhoea.

Bone marrow transplant: A two-decade single centre hematology experience.

Background: Bone Marrow Transplant (BMT) is a curative form of therapy for many hematological disorders in both the adult and pediatric patients. The availability of BMT in the AFMS at AHRR for the last 02 decades has been a game changer for the patients. Methods: We reviewed our BMT data since the inception of the program till Feb 2023. Results: Over 700 patients with more than 23 different types of hematological disorders have undergone this procedure 58%% patients underwent an Autologous BMT and 42% an allogenic BMT. Autologous BMT for Multiple Myeloma and Allogenic BMT for Aplastic Anemia and Acute Leukemias have been the most common indications. 73% patients were adults, and 27% patients were of the pediatric age group. The male: female ratio was 2:1. The spectrum of allogenic Hematopoietic Stem Cell Transplant (HSCT) has expanded from Matched Sibling Donor (MSD) transplants to Matched Unrelated Donor (MUD) Transplants and Haploidentical Donor Transplants. 93% of our Allogenic BMT patients underwent a MSD BMT, 1% MUD BMT and 06% Haploidentical BMT. Today no patient with a malignant hematological disorder requiring a BMT is denied the procedure due to the lack of an HLA donor due to the availability of haploidentical BMT. Conclusion: The evolution of a BMT program has a long learning curve and the expanded pool of eligible donors has led to a situation of "transplant for all". Haploidentical HSCT for nonmalignant hematological disorders is an unmet need. CART cell therapy and Cellular therapies need to be prioritized for future inclusion.