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1.
Phys Rev Lett ; 131(9): 091801, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37721818

RESUMO

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.

2.
Phys Rev Lett ; 128(9): 090401, 2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35302825

RESUMO

In the expanding universe, relativistic scalar fields are thought to be attenuated by "Hubble friction," which results from the dilation of the underlying spacetime metric. By contrast, in a contracting universe this pseudofriction would lead to amplification. Here, we experimentally measure, with fivefold better accuracy, both Hubble attenuation and amplification in expanding and contracting toroidally shaped Bose-Einstein condensates, in which phonons are analogous to cosmological scalar fields. We find that the observed attenuation or amplification depends on the temporal phase of the phonon field, which is only possible for nonadiabatic dynamics. The measured strength of the Hubble friction disagrees with recent theory [Gomez Llorente et al., Phys. Rev. A 100, 043613 (2019)PLRAAN2469-992610.1103/PhysRevA.100.043613 and Eckel et al., SciPost Phys. 10, 64 (2021)SPCHCW2542-465310.21468/SciPostPhys.10.3.064].

3.
Phys Rev Lett ; 127(6): 061801, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34420312

RESUMO

We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σ_{E}=3.86±0.04(stat)_{-0.00}^{+0.19}(syst) eV. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140 MeV/c^{2}, with a raw exposure of 9.9 g d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.

4.
Phys Rev Lett ; 127(8): 081802, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34477436

RESUMO

The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) achieved efficient detection of very small recoil energies in its germanium target, resulting in sensitivity to lightly ionizing particles (LIPs) in a previously unexplored region of charge, mass, and velocity parameter space. We report first direct-detection limits calculated using the optimum interval method on the vertical intensity of cosmogenically produced LIPs with an electric charge smaller than e/(3×10^{5}), as well as the strongest limits for charge ≤e/160, with a minimum vertical intensity of 1.36×10^{-7} cm^{-2} s^{-1} sr^{-1} at charge e/160. These results apply over a wide range of LIP masses (5 MeV/c^{2} to 100 TeV/c^{2}) and cover a wide range of ßγ values (0.1-10^{6}), thus excluding nonrelativistic LIPs with ßγ as small as 0.1 for the first time.

6.
Anaesthesist ; 68(11): 780-783, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31686115

RESUMO

Super obesity with a body mass index (BMI) >50 kg/m2 presents a challenge for the neuroanesthesiologist during awake craniotomy procedures and poses increased perioperative risk of complications, even vis-à-vis morbid obesity. This article presents a super obese patient (BMI 57 kg/m2) with drug-refractory epilepsy and obstructive sleep apnea who underwent left anterior temporal lobectomy through awake craniotomy to preserve language and memory, using warmed humidified high flow nasal cannula (HFNC) oxygen therapy. Awake craniotomy was facilitated by the use of HFNC, which proved essential to prevent airway collapse by creating continuous positive airway pressure through high flow and facilitated intraoperative neurologic language and memory testing while maintaining adequate oxygenation.


Assuntos
Cânula , Craniotomia , Oxigenoterapia , Pressão Positiva Contínua nas Vias Aéreas , Epilepsia , Humanos , Obesidade , Apneia Obstrutiva do Sono
7.
Phys Rev Lett ; 120(6): 061802, 2018 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-29481237

RESUMO

We report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP-nucleon cross section of 1.4×10^{-44} (1.0×10^{-44}) cm^{2} at 46 GeV/c^{2}. These results set the strongest limits for WIMP-germanium-nucleus interactions for masses >12 GeV/c^{2}.

8.
Phys Rev Lett ; 121(5): 051301, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-30118251

RESUMO

We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 g CDMS high-voltage device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1 MeV/c^{2}. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 g d). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations.

9.
Reprod Domest Anim ; 52(2): 183-188, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27862454

RESUMO

The objective of the present study was to investigate the effect of testicular tissue lysate (TTL) on developmental competence of germinal vesicle (GV) stage porcine oocytes. Two types of TTL were prepared through repeated freeze-thaw in liquid nitrogen, one from whole testicular tissue (wTTL) and other from either of four different sections of testes, namely just beneath the tunica albuginea (TA), from the transitional area between the seminiferous cord/tubules and the mediastinum testis (TR) and from the intermediate area (parenchymal tissue origin) and CE (cauda epididymis origin). The whole or section-wise TTL treatments were given for 44 hr during in vitro maturation (IVM). Oocyte maturation was done in either of the two media, namely defined (high-performance basic medium for porcine oocyte maturation, commercially available) and serum containing (TCM199). After maturation, oocytes were co-incubated with fresh spermatozoa for 6 hr and then transferred to embryo culture media. Treatment of GV stage oocytes with wTTL (1 mg/ml) increased the cleavage and morula percentage rate (69.23 ± 6.23 and 48.15 ± 6.77, respectively) than that of their control (58.33 ± 8.08 and 32.54 ± 5.53, respectively) in defined media, and in serum-containing media, cleavage and morula percentage rate were almost equal in both treatment (54.56 ± 7.79 and 34.70 ± 6.78, respectively) and control (59.52 ± 8.21 and 38.52 ± 6.54, respectively). However, effect of wTTL was not significant. In case of section-wise TTL supplements, TR section significantly (p < .01) improved cleavage and morula rate (58.43 ± 7.98 and 36.14 ± 6.89, respectively) followed by TA. In conclusion, present study indicates that IVM, in vitro fertilization and in vitro culture of embryo are improved in the presence of TTL, particularly its TR section. Further study is expected to reveal the principal components of TTL which may prove useful for IVM.


Assuntos
Fertilização in vitro/veterinária , Técnicas de Maturação in Vitro de Oócitos/veterinária , Oócitos/fisiologia , Suínos/fisiologia , Testículo/química , Animais , Feminino , Masculino , Testículo/fisiologia
10.
Mymensingh Med J ; 23(3): 480-4, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25178599

RESUMO

Early onset of hyperglycemia is common among low birth weight neonates. Increased risk for death and major morbidities has been observed among hyperglycemic low birth weight infants. This prospective observational study was done to find out hyperglycemia as a predictor of increased morbidity and mortality in the low birth weight sick newborn and was conducted among the hospitalized newborn of Special Care Baby Unit (SCABU), BIRDEM hospital, Dhaka, Bangladesh from July 2009 to December 2009. A total of 198 LBW neonates were included in this study. One third (30.8%) LBW neonates were found hyperglycemic. The mean gestational age was 33.2±3.6 weeks and mean birth weight was 1535.8±780gm in the hyperglycemic neonates. In this study, highest prevalence of hyperglycemia was observed in birth weight <1000gm (38.46%) and in gestational age ≤28 weeks (46.15%). Apnoea, confirmed sepsis and suspected sepsis, confirmed necrotizing enterocollitis (NEC) and neonatal jaundice showed statistically significant association with hyperglycemia than that of non hyperglycemic group. Mortality of neonates in hyperglycemic group was higher (31.15%) than that of non hyperglycemic neonates (10.22%) and the difference in mortality between two groups were found statistically significant (p<0.002). From this study it can be concluded that hyperglycemia in early neonatal period is related to increased morbidity and mortality in low birth weight newborn.


Assuntos
Hiperglicemia/mortalidade , Mortalidade Infantil , Recém-Nascido de Baixo Peso , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Morbidade , Estudos Prospectivos
11.
Mymensingh Med J ; 32(1): 135-143, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36594313

RESUMO

Tumors in the hand are relatively uncommon but 95% are benign. Tumors occurring in the hand, forearm and arm often have unique growth patterns and potential for metastasis that may be different from those seen elsewhere in the body. Secondary metastatic tumors in the hand are very rare (0.1%). Diagnosis is mainly clinical, but X-ray, USG and MRI help as a diagnostic aid. The aim of the study was to early diagnosis, see the pattern and proper management of the hand tumor and ensure good hand function. This prospective study was done from January 2004 to July 2019. We found 220 hand tumors in the hand unit, Department of Orthopaedic Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka Bangladesh. Among 220 patients, male were 114(51.81%) and female were 106 (48.19%). Out of 220 patients we found 190(86.36%) benign tumor and tumor like lesions and 30(13.64%) was malignant hand tumors. Out of 190 benign lesions, benign tumor was 158(83.15%) and 32(16.85%) was tumor like lesions. Among 158 benign tumor, bone tumors were 40(25.31%) and soft tissue tumours were 138(74.69%). Out of soft tissue tumor, peripheral nerve tumor was 20(12.66%). Enchondroma and Giant cell tumors are the most common among the benign bone tumors, on the other hand giant cell tumors of tendon sheath, Glomus tumor, haemangioma, neurofibroma, schwanoma are the common soft tissue tumors. Compound palmar ganglion, fibromatosis and tuberculosis of phalanx are the most common tumor like lesions. Synovial sarcoma 10(33.33%), osteosarcoma 03(10%), chondrosarcoma 03(10%), ewings sarcoma 02(6.66%), fibrosarcoma 04 (13.33%), Malignant fibrous histocytoma 01(3.33%), soft tissue sarcoma 01(3.33%), Merkel cell tumor 01(3.33%), pleomorphic Rabdomyosarcoma 01(3.33%), malignant melanoma 01(3.33%), clear cell sarcoma of tendon and aponeurosis 01(3.33%), undifferentiated carcinoma 01(3.33%) and extra skeletal chondro sarcoma 01(3.33%) were the malignant tumors. Most of the benign lesions recovered fully after excision except neurofibroma and malignant tumors were treated with excision (including amputation) and chemo-radiotherapy successfully, but 4 patients were refereed to higher center due to recurrence and deteriation of hand function and one patient died due to metastasis. Malignant hand tumor management is very difficult even after amputation with multidisciplinary approach. Hand tumor is uncommon and malignant tumors are rare but any abnormal lump or bump in the hand or wrist is considered as tumor. Early detection and intervention are essential for better prognosis and survival for malignant tumors of hands and upper limbs.


Assuntos
Neoplasias Ósseas , Tumores de Células Gigantes , Tumor Glômico , Neurofibroma , Neoplasias de Tecidos Moles , Humanos , Masculino , Feminino , Estudos Prospectivos , Bangladesh/epidemiologia , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/terapia , Neoplasias de Tecidos Moles/diagnóstico , Neoplasias de Tecidos Moles/terapia , Neoplasias de Tecidos Moles/patologia , Punho/patologia
12.
Eur Phys J Plus ; 138(1): 100, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36741916

RESUMO

The CRESST experiment employs cryogenic calorimeters for the sensitive measurement of nuclear recoils induced by dark matter particles. The recorded signals need to undergo a careful cleaning process to avoid wrongly reconstructed recoil energies caused by pile-up and read-out artefacts. We frame this process as a time series classification task and propose to automate it with neural networks. With a data set of over one million labeled records from 68 detectors, recorded between 2013 and 2019 by CRESST, we test the capability of four commonly used neural network architectures to learn the data cleaning task. Our best performing model achieves a balanced accuracy of 0.932 on our test set. We show on an exemplary detector that about half of the wrongly predicted events are in fact wrongly labeled events, and a large share of the remaining ones have a context-dependent ground truth. We furthermore evaluate the recall and selectivity of our classifiers with simulated data. The results confirm that the trained classifiers are well suited for the data cleaning task.

13.
Appl Radiat Isot ; 194: 110670, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36696751

RESUMO

CRESST is a leading direct detection sub-GeVc-2 dark matter experiment. During its second phase, cryogenic bolometers were used to detect nuclear recoils off the CaWO4 target crystal nuclei. The previously established electromagnetic background model relies on Secular Equilibrium (SE) assumptions. In this work, a validation of SE is attempted by comparing two likelihood-based normalisation results using a recently developed spectral template normalisation method based on Bayesian likelihood. Albeit we find deviations from SE in some cases we conclude that these deviations are artefacts of the fit and that the assumptions of SE is physically meaningful.

14.
Phys Rev Lett ; 109(24): 246601, 2012 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-23368355

RESUMO

Spin valves have revolutionized the field of magnetic recording and memory devices. Spin valves are generally realized in thin film heterostructures, where two ferromagnetic (FM) layers are separated by a nonmagnetic conducting layer. Here, we demonstrate spin-valve-like magnetoresistance at room temperature in a bulk ferrimagnetic material that exhibits a magnetic shape memory effect. The origin of this unexpected behavior in Mn(2)NiGa has been investigated by neutron diffraction, magnetization, and ab initio theoretical calculations. The refinement of the neutron diffraction pattern shows the presence of antisite disorder where about 13% of the Ga sites are occupied by Mn atoms. On the basis of the magnetic structure obtained from neutron diffraction and theoretical calculations, we establish that these antisite defects cause the formation of FM nanoclusters with parallel alignment of Mn spin moments in a Mn(2)NiGa bulk lattice that has antiparallel Mn spin moments. The direction of the Mn moments in the soft FM cluster reverses with the external magnetic field. This causes a rotation or tilt in the antiparallel Mn moments at the cluster-lattice interface resulting in the observed asymmetry in magnetoresistance.

15.
Folia Morphol (Warsz) ; 81(3): 777-780, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34060641

RESUMO

BACKGROUND: Variation in the posterior cord of the brachial plexus is complicated and creates a risky relationship with the neighbouring structures. This is of importance to the surgeons and anaesthetists who must deal with the region in surgeries and procedures. Moreover, any benign tumour like schwannoma is rare in the plexus comprising 5% of total head and neck schwannomas. MATERIALS AND METHODS: We present a case of schwannoma of the brachial plexus in a cadaver during routine anatomy dissection for the medical students. The origin and order of branching of the posterior cord were recorded and photographs were taken. The tumour was present in an accessory branch of the posterior cord and removal was made in-toto. An immunohistochemistry study was done for confirmation of diagnosis. RESULTS: The classical branching of the posterior cord was present. Additionally, a branch existed that was supplying the triceps muscle and emerged directly from the posterior cord. Tumour having the dimension of 2 × 1.8 × 0.5 cm was present. CONCLUSIONS: Schwannomas are indolent but may cause compression of the nerve and resulting neurological symptoms. They might mimic nodules of supraclavicular fossa in breast carcinoma. Variations of the brachial plexus can also make the surgeons confused during surgery due to which anatomical knowledge of the possible variations is important. Pre- and post-operative complications can be easily predicted from it. Follow-up of the tumour is essential to track its progress and differentiation.


Assuntos
Plexo Braquial , Neurilemoma , Cadáver , Dissecação , Humanos , Pescoço , Neurilemoma/cirurgia
16.
Mymensingh Med J ; 31(4): 1048-1056, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36189551

RESUMO

Avascular necrosis (AVN) of femoral head is an increasingly common cause of musculoskeletal disability. Most of the cases caused by steroid induced and traumatic but idiopathic cause are not also uncommon. Almost all the patients presented with pain at the hip, limping gait, restricted movement and difficulty in waking and squatting and becomes disabled. Core decompression and muscle pedicle bone graft at stage IIA, IIB and III provides painless and mobile life. Core decompression supplemented with bone graft to enhance mechanical support and augment healing. We have started a prospective study for the treatment of AVN of Femoral head at stage IIA, IIB and III by core decompression and Tensor fascia lata muscle pedicle bone graft in the department of Orthopaedic surgery Bangabandhu Seikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2009 to December 2019. Aim of the study was to assess the effectiveness of core decompression and tensor fascia lata muscle pedicle bone graft in the treatment of AVN of femoral head at stage IIA, IIB and III. A total 48 patients and 65 hips were operated. Out of 48 patients, male was 30(62.50%) and female was 18(37.5%). Male-Female ratio was 1.66:1. Age of the patients ranging from 20 years to 50 years, mean age 36±4.65 years. According to aetiology corticosteroid induced was 47/65 (72.31%), idiopathic was 8(12.31%), post traumatic was 4(6.15%), ITP was 2(3.08%), ALL was 2(3.08%), and alcohol induced was 2(3.08%) of femoral head involvement. According to Ficat and Arlet's staging, stage IIA hip involvement was 28/65(43.08%), stage IIB was 32(49.23%) and stage III was 5(07.69%). All patients were treated with core decompression along with tensor fascia lata (TFL) muscle pedicle bone graft. All patients were followed clinically and radiologically at regular interval. Follow up period was 6 months to 10 years. Harris hip score (HHS) was used for evaluation of clinical outcome. Among the 65 hips, 24(36.92%) was excellent outcome (HHS >90), 30(46.15%) was good outcome (HHS: 80-90), 7(10.78%) was fair outcome (HHS: 70-79) and 4(6.15%) was poor outcome. For valid statistical analysis excellent and good results were grouped as satisfactory that was 54(83.07%) and fair and poor results were grouped as unsatisfactory that was11(16.93%), p value is <0.001 that is significant. It has been concluded that core decompression and TFL muscle pedicle bone graft is a pain relieving, head preserving procedure and improve hip function for the management of AVN of femoral head in stage IIA, IIB and III.


Assuntos
Necrose da Cabeça do Fêmur , Cabeça do Fêmur , Adulto , Bangladesh , Transplante Ósseo/efeitos adversos , Transplante Ósseo/métodos , Descompressão Cirúrgica/efeitos adversos , Descompressão Cirúrgica/métodos , Fascia Lata/cirurgia , Feminino , Cabeça do Fêmur/cirurgia , Necrose da Cabeça do Fêmur/etiologia , Necrose da Cabeça do Fêmur/cirurgia , Humanos , Masculino , Músculo Esquelético/cirurgia , Dor , Estudos Prospectivos , Resultado do Tratamento , Adulto Jovem
17.
Phys Chem Chem Phys ; 13(11): 4812-29, 2011 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-21258671

RESUMO

Chiral interfaces and molecular recognition phenomena are of special interest not only for the understanding of biological recognition processes but also for the potential application in material science. Langmuir monolayers at the air-water interface have successfully been used as simple models to mimic biological phenomena. Recent experimental studies revealed that both chirality and molecular recognition processes of amphiphiles are controlling the features of the nano-aggregates at the air/water interface. The objective of experimental studies has been to gain information about the properties of mesoscopic length scale aggregates obtained on the basis of chiral discrimation effects and the formation of supramolecular entities by molecular recognition of non-surface active species dissolved in the aqueous subphase. Differences in the two-dimensional morphology and lattice structures of the nano-aggregates cannot be explained by macroscopic theories and needed information about the detailed orientation and distance dependence of the intermolecular interaction within the aggregates. First new bottom-up studies have been directed toward understanding the driving forces for the aggregation processes of monolayers. Different types of interactions have been successfully considered using semi-empirical quantum chemical methods. The possibilities of Langmuir-Blodgett (LB) patterning to be an alternative paradigm for large-area patterning with mesostructured features are discussed.

18.
Mymensingh Med J ; 30(1): 73-78, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33397854

RESUMO

In adults, distal humerus fractures are infrequent and frequently intra-articular. Customarily encompass both medial and lateral columns. Operative management gives constructive outcomes. The aim of this study was to evaluate clinical outcome in intra articular distal humerus fractures in adults treated by different hardware. This prospective study consists of 20 purposively selected patients with intra articular distal humerus fractures treated by surgical intervention with different hardware who were admitted to Mymensingh Medical College and Hospital, Bangladesh in between November 2016 to October 2018. Surgical approaches were standard dorsal with or without olecranon osteotomy. The mean age of the patients was 32.3 years, range between 18-55 years. The maximum patients i.e. 85% were between 18-45 years. Seventy percent (70%) of the cases admitted were due to Road traffic accident (RTA). Most of the patients were males 14(70%) with right upper limb was involved in 13(65%) cases. Mean Mayo Elbow Performance Score was 81.5 post-operatively. According to Mayo Elbow Performance (MEP) score clinical outcome was excellent in 20%, good in 50%, fair in 25% and poor in 10% of patients. Distal humerus fractures are censorious in nature. Proper anatomical articular reconstruction and stable fixation by surgical intervention helps in fruitful results.


Assuntos
Articulação do Cotovelo , Fraturas do Úmero , Adolescente , Adulto , Bangladesh/epidemiologia , Articulação do Cotovelo/cirurgia , Fixação Interna de Fraturas , Humanos , Fraturas do Úmero/cirurgia , Úmero , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Amplitude de Movimento Articular , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
19.
Mymensingh Med J ; 30(2): 410-414, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33830121

RESUMO

The aim of the present study was to compare the sensitivity between Alvarado and RIPASA score for the diagnosis of acute appendicitis patients. A comparative study was conducted in the Dhaka National Medical College Hospital, Bangladesh from July 2015 to December 2015. The study was approved by the institutional ethical committee. Most of the appendicitis patients belonged to the between 21-30 years which was 64(32%). Male appendicitis patients (52%) are more than the female patients (48%). Majority of the patients (69%) complains pain occurs in the Right iliac fossa. Sensitivity of Alvarado scores was 81.60%, specificity 74.58%, accuracy 79.35%, positive and negative predictive values were 87.18% and 65.67% respectively. RIPASA score's sensitivity was 85.6%, specificity 69.49%, accuracy 80.40%, positive and negative predictive values were 85.60% and 85.60% respectively. This study reported that RIPASA score is significantly shown higher diagnostic accuracy then that Alvarado score.


Assuntos
Apendicite , Doença Aguda , Apendicectomia , Apendicite/diagnóstico , Bangladesh/epidemiologia , Feminino , Humanos , Masculino , Estudos Prospectivos , Sensibilidade e Especificidade
20.
PLoS One ; 15(6): e0234395, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32525930

RESUMO

As rice is an important staple food globally, research for development and enhancement of its nutritional value it is an imperative task. Identification of nutrient enriched rice germplasm and exploiting them for breeding programme is the easiest way to develop better quality rice. In this study, we analyzed 113 aromatic rice germplasm in order to identify quantitative trait loci (QTL) underpinning nutrition components and determined by measuring the normal frequency distribution for Fe, Zn, amylose, and protein content in those rice germplasm. Comparatively, the germplasm Radhuni pagal, Kalobakri, Thakurbhog (26.6 ppm) and Hatisail exhibited the highest mean values for Fe (16.9 ppm), Zn (34.1 ppm), amylose (26.6 ppm) and protein content (11.0 ppm), respectively. Moreover, a significant linear relationship (R2 = 0.693) was observed between Fe and Zn contents. Cluster analysis based on Mahalanobis D2 distances revealed four major clusters of 113 rice germplasm, with cluster III containing a maximum 37 germplasm and a maximum inter-cluster distance between clusters III and IV. The 45 polymorphic SSRs and four trait associations exhibited eight significant quantitative trait loci (QTL) located on eight different chromosomes using composite interval mapping (CIM). The highly significant QTL (variance 7.89%, LOD 2.02) for protein content (QTL.pro.1) was observed on chromosome 1 at 94.9cM position. Also, four QTLs for amylose content were observed with the highly significant QTL.amy.8 located on chromosome 8 exhibiting 7.2% variance with LOD 1.83. Only one QTL (QTL.Fe.9) for Fe content was located on chromosome 9 (LOD 1.24), and two (QTL.Zn.4 and QTL.Zn.5) for Zn on chromosome 4 (LOD 1.71) and 5 (LOD 1.18), respectively. Overall, germplasm from clusters III and IV might offer higher heterotic response with the identified QTLs playing a significant role in any rice biofortification breeding program and released with development of new varieties.


Assuntos
Oryza/genética , Locos de Características Quantitativas , Amilose/análise , Biofortificação/métodos , Produtos Agrícolas/química , Produtos Agrícolas/classificação , Produtos Agrícolas/genética , Alimentos Fortificados/análise , Genes de Plantas , Marcadores Genéticos , Ferro/análise , Valor Nutritivo , Oryza/química , Oryza/classificação , Fenótipo , Melhoramento Vegetal/métodos , Proteínas de Vegetais Comestíveis/análise , Análise de Regressão , Sementes/química , Sementes/genética , Zinco/análise
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