RESUMO
Compressing the optical field to the atomic scale opens up possibilities for directly observing individual molecules, offering innovative imaging and research tools for both physical and life sciences. However, the diffraction limit imposes a fundamental constraint on how much the optical field can be compressed, based on the achievable photon momentum1,2. In contrast to dielectric structures, plasmonics offer superior field confinement by coupling the light field with the oscillations of free electrons in metals3-6. Nevertheless, plasmonics suffer from inherent ohmic loss, leading to heat generation, increased power consumption and limitations on the coherence time of plasmonic devices7,8. Here we propose and demonstrate singular dielectric nanolasers showing a mode volume that breaks the optical diffraction limit. Derived from Maxwell's equations, we discover that the electric-field singularity sustained in a dielectric bowtie nanoantenna originates from divergence of momentum. The singular dielectric nanolaser is constructed by integrating a dielectric bowtie nanoantenna into the centre of a twisted lattice nanocavity. The synergistic integration surpasses the diffraction limit, enabling the singular dielectric nanolaser to achieve an ultrasmall mode volume of about 0.0005 λ3 (λ, free-space wavelength), along with an exceptionally small feature size at the 1-nanometre scale. To fabricate the required dielectric bowtie nanoantenna with a single-nanometre gap, we develop a two-step process involving etching and atomic deposition. Our research showcases the ability to achieve atomic-scale field localization in laser devices, paving the way for ultra-precise measurements, super-resolution imaging, ultra-efficient computing and communication, and the exploration of light-matter interactions within the realm of extreme optical field localization.
RESUMO
Miniaturized lasers play a central role in the infrastructure of modern information society. The breakthrough in laser miniaturization beyond the wavelength scale has opened up new opportunities for a wide range of applications1-4, as well as for investigating light-matter interactions in extreme-optical-field localization and lasing-mode engineering5-19. An ultimate objective of microscale laser research is to develop reconfigurable coherent nanolaser arrays that can simultaneously enhance information capacity and functionality. However, the absence of a suitable physical mechanism for reconfiguring nanolaser cavities hinders the demonstration of nanolasers in either a single cavity or a fixed array. Here we propose and demonstrate moiré nanolaser arrays based on optical flatbands in twisted photonic graphene lattices, in which coherent nanolasing is realized from a single nanocavity to reconfigurable arrays of nanocavities. We observe synchronized nanolaser arrays exhibiting high spatial and spectral coherence, across a range of distinct patterns, including P, K and U shapes and the Chinese characters '' and '' ('China' in Chinese). Moreover, we obtain nanolaser arrays that emit with spatially varying relative phases, allowing us to manipulate emission directions. Our work lays the foundation for the development of reconfigurable active devices that have potential applications in communication, LiDAR (light detection and ranging), optical computing and imaging.
RESUMO
BACKGROUND AND OBJECTIVES: In urology, potassium-titanyl-phosphate (KTP) laser is mainly used in the treatment of benign prostatic hyperplasia with a low rate of intraoperative and postoperative complications. A prospective, randomized study was undertaken to investigate the treatment outcomes of KTP laser vaporization for primary non-muscle-invasive bladder tumors (NMIBTs) as compared with conventional monopolar transurethral resection of bladder tumors (TURBT). MATERIALS AND METHODS: This study was designed as a prospective, randomized trial. After institutional review board approval, 229 consecutive patients with NMIBTs were randomized to 2 groups. Among them, 116 patients underwent KTP laser vaporization of a bladder tumor (laser group) and 113 patients underwent standard transurethral electroresection of the bladder tumors using monopolar loop electrode (TURBT group). According to the prognostic factors for recurrence, all patients were divided into low, intermediate or high risk subgroups. The clinical data were recorded and compared between the two groups. RESULTS: Eighty-nine patients in laser group and 94 in TURBT group were evaluable for the study end points. The preoperative characteristics of the patients were comparable in the two groups. There was no statistical difference in operation time between the two groups. Patients in the laser group had fewer perioperative complications and more patients needed bladder irrigation in the TURBT group. Compared with laser group, patients in the TURBT group had longer catheterization time and hospitalization duration. There were no statistical differences in the oncologic results in term of 2-year recurrence rates as compared between the two groups. CONCLUSIONS: Our study demonstrated that using KTP laser, transurethral vaporization is an effective and safe treatment for the patients with primary NMIBT. Compared with traditional TURBT, the KTP laser surgery had fewer perioperative complications and similar oncological results.
Assuntos
Eletrocirurgia/métodos , Terapia a Laser , Lasers de Estado Sólido , Neoplasias da Bexiga Urinária/cirurgia , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Hemorragia Pós-Operatória/terapia , Estudos Prospectivos , Irrigação Terapêutica/estatística & dados numéricos , Cateterismo Urinário/estatística & dados numéricosRESUMO
BACKGROUND AND AIMS: Mercury (Hg) is an extremely toxic pollutant, especially in the form of methylmercury (MeHg), whereas selenium (Se) is an essential trace element in the human diet. This study aimed to ascertain whether addition of Se can produce rice with enriched Se and lowered Hg content when growing in Hg-contaminated paddy fields and, if so, to determine the possible mechanisms behind these effects. METHODS: Two cultivars of rice (Oryza sativa, japonica and indica) were grown in either hydroponic solutions or soil rhizobags with different Se and Hg treatments. Concentrations of total Hg, MeHg and Se were determined in the roots, shoots and brown rice, together with Hg uptake kinetics and Hg bioavailability in the soil. Root anatonmy was also studied. KEY RESULTS: The high Se treatment (5 µg g(-1)) significantly increased brown rice yield by 48 % and total Se content by 2·8-fold, and decreased total Hg and MeHg by 47 and 55 %, respectively, compared with the control treatments. The high Se treatment also markedly reduced 'water-soluble' Hg and MeHg concentrations in the rhizosphere soil, decreased the uptake capacity of Hg by roots and enhanced the development of apoplastic barriers in the root endodermis. CONCLUSIONS: Addition of Se to Hg-contaminated soil can help produce brown rice that is simultaneously enriched in Se and contains less total Hg and MeHg. The lowered accumulation of total Hg and MeHg appears to be the result of reduced bioavailability of Hg and production of MeHg in the rhizosphere, suppression of uptake of Hg into the root cells and an enhancement of the development of apoplastic barriers in the endodermis of the roots.
Assuntos
Mercúrio/metabolismo , Oryza/anatomia & histologia , Oryza/metabolismo , Raízes de Plantas/anatomia & histologia , Rizosfera , Selênio/farmacologia , Disponibilidade Biológica , Cinética , Compostos de Metilmercúrio , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Raízes de Plantas/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Solo/química , Solubilidade , Água/químicaRESUMO
OBJECTIVE: To evaluate the feasibility and safety of applying video endoscopic inguinal lymphadenectomy via hypogastric subcutaneous approach (VEIL-H) in the treatment of vulvar carcinoma. METHODS: From September 2009 to December 2012, 15 patients with vulvar carcinoma underwent VEIL-H plus radical vulvectomy at many participating hospitals. RESULTS: All were treated surgically. Two of them underwent laparoscopic pelvic lymphadenectomy (LPL) upon the positive results of parotid operations with frozen section. The mean operative duration of VEIL-H (bilateral groin) were (80.8 ± 2.9) minutes. The mean total volume of blood loss in VEIL was (5.5 ± 0.4) ml, the mean drainage duration (6 ± 2) days and the average postoperative hospitalization (11 ± 4) days. The mean follow-up period was 13.0 months. One patient suffered local recurrence at Month 2 postoperation. CONCLUSION: VEIL-H is both feasible and safe in inguinal lymphadenectomy.
Assuntos
Virilha , Laparoscopia , Excisão de Linfonodo/métodos , Neoplasias Vulvares/cirurgia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: To evaluate the efficacy and safty of photoselective vaporization of prostate (PVP) in the treatment of benign prostatic hyperplasia with obstruction within 5 years. METHODS: From December 2004 to December 2009, there were 782 cases have been except for neurogenic bladder dysfunction and prostate cancer, who received PVP surgical treatment of BPH. The surgical conditions and postoperative follow-up data were recorded and the follow-up cut-off time for surgery after 5 years. RESULTS: A total of 782 patients with BPH who underwent PVP were included in this retrospective study. The operation in 740 cases was successfully completed at one time. But in other 42 cases, the twice operation was performed. The mean operation time was (85 ± 38) minutes, and the mean energy delivery was (355 ± 124) kJ. The mean catheterization and postoperative hospitalization time was (2.3 ± 1.7) days and (5.2 ± 2.6) days, respectively. No severe intraoperative complications were observed. The mean follow-up was (44.1 ± 19.3) months. The shortest follow-up was 6 months. The longest follow-up was 5 years. Complete follow-up data were available for 398 of the 782 patients. Of the 398 patients followed up for 5 years, the mean international prostate symptom score after 5 years was 12.8 ± 6.9, quality of life score was 2.2 ± 1.6, maximal flow rate was (14.5 ± 2.4) ml/s, and residual urine volume was 58 ml (M50). The retreatment rate because of BPH was 2.3% (9/398). Urethral stricture and bladder neck contracture were observed in 1.5% and 0.5% of the patients, respectively. CONCLUSIONS: PVP has demonstrated remarkably consistent results for objective and subjective voiding parameters. Its late complication is rare and retreatment rate is low.
Assuntos
Lasers de Estado Sólido , Hiperplasia Prostática/cirurgia , Ressecção Transuretral da Próstata , Idoso , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Simultaneous localization of light to extreme spatial and spectral scales is of high importance for testing fundamental physics and various applications. However, there is a longstanding trade-off between localizing a light field in space and in frequency. Here we discover a new class of twisted lattice nanocavities based on mode locking in momentum space. The twisted lattice nanocavity hosts a strongly localized light field in a 0.048 λ3 mode volume with a quality factor exceeding 2.9 × 1011 (â¼250 µs photon lifetime), which presents a record high figure of merit of light localization among all reported optical cavities. Based on the discovery, we have demonstrated silicon-based twisted lattice nanocavities with quality factor over 1 million. Our result provides a powerful platform to study light-matter interaction in extreme conditions for tests of fundamental physics and applications in nanolasing, ultrasensing, nonlinear optics, optomechanics and quantum-optical devices.
RESUMO
Background: Ultrasonography of the uterine artery (UtA) in the first and second trimesters of pregnancy can assess uterine-placental blood perfusion and guide early clinical prevention. Establishing normal ranges of the UtA pulsatility index (UtA-PI) at 11-14 weeks of pregnancy is helpful for the early identification of high-risk pregnant women and improving the prognosis. This study aimed to establish a reference range of UtA-PI based on crown-rump length (CRL) for spontaneous and in vitro fertilization (IVF) singleton pregnancy during 11-14 weeks, respectively. Methods: A prospective study was performed at Peking Union Medical College Hospital. Healthy, low-risk women with a singleton pregnancy at 11-14 gestational weeks were consecutively recruited for this study from December 2017 to December 2020. All participants underwent routine prenatal ultrasound examination. The CRL of the fetus and the UtA-PI were measured in both uterine arteries, and average values were calculated. The LMS method was used to fit the percentile (P)5, P10, P25, P50, P75, P90, and P95 curves of the UtA-PI value of spontaneous and IVF singleton pregnancy with CRL changes, respectively. Results: A total of 1,962 pregnant women with normal fetuses were included in this study, including 1,792 pregnancies conceived naturally and 170 IVF fetuses. The UtA-PI reference range in the spontaneous pregnancy group was consistently higher than that in the IVF group during 11-14 weeks, and showed a statistically significant difference in UtA-PI for spontaneous and IVF pregnancies (P<0.001). According to the LMS method, each percentile curve of UtA-PI decreased with the increase of CRL in both the natural pregnancy group and the IVF group. The P95 range of UtA-PI for pregnant women with naturally conceived and IVF pregnancy was 2.74 to 2.11 and 2.50 to 1.94, respectively. The overall change of UtA-PI differentials of the two groups showed a downward trend and decreased slightly with the increase of CRL. Conclusions: This study provided a single-center, large sample of data and constructed a CRL-based reference value of UtA-PI for spontaneous and IVF singleton pregnancy, which provides a reliable basis for early UtA evaluation and early clinical decision-making during 11-14 gestational weeks.
RESUMO
Hepatitis E virus (HEV) is an enteric pathogen of humans and animals, and pigs have been considered an important reservoir of this virus. Recent evidence has indicated the cross-species transmission of hepatitis E virus (HEV) from pigs to humans, causing zoonosis, mostly via consumption of uncooked or undercooked animal meat/viscera. In this study, we have developed a one-step RT-LAMP assay for rapid detection of swine HEV. Specific primer sets targeting the ORF3 gene were designed. The sensitivity of the RT-LAMP assay was 10(1) copies/µl of RNA template, which was tenfold higher than that of RT-nPCR. The specificity of this assay was demonstrated by the lack of amplification of DNA/RNA from other swine viruses. Furthermore, a total of 41 bile samples were subjected to RT-LAMP and RT-nPCR. Eighteen positive samples were detected by RT-nPCR, while 36 positive samples were detected by RT-LAMP, indicating that the sensitivity of the RT-LAMP assay was higher than that of the conventional RT-nPCR assay. The RT-LAMP assay reported here may be used for diagnosis of swine HEV, not only in laboratories but also under field conditions.
Assuntos
Vírus da Hepatite E/isolamento & purificação , Hepatite E/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária , Doenças dos Suínos/virologia , Animais , Bile/virologia , Regulação Viral da Expressão Gênica , Hepatite E/diagnóstico , Hepatite E/virologia , Vírus da Hepatite E/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Filogenia , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/diagnósticoRESUMO
Bound states in the continuum (BICs) in photonic crystals describe the originally leaky Bloch modes that can become bounded when their radiation fields carry topological polarization singularities. However, topological polarization singularities do not carry energy to far field, which limits radiation efficiencies of BICs for light emitting applications. Here, we demonstrate a topological polarization singular laser which has a topological polarization singular channel in the second Brillouin zone and a paired linearly polarized radiation channel in the first Brillouin zone. The presence of the singular channel enables the lasing mode with a higher quality factor than other modes for single mode lasing. In the meanwhile, the presence of the radiation channel secures the lasing mode with high radiation efficiency. The demonstrated topological polarization singular laser operates at room temperature with an external quantum efficiency exceeding 24%. Our work presents a new paradigm in eigenmode engineering for mode selection, exotic field manipulation and lasing.
RESUMO
Modeling and prediction of H2S emission from wastewater are important since gaseous H2S will induce significant corrosion and odor problems. Most previous studies focused on H2S emission of wastewater in pipeline systems, which may not be fit for H2S emission in wastewater treatment plants (WWTPs). This study provided a two-phase mass transfer model for prediction of H2S emission concentrations. The model is based on the mass transfer rate equation of the mass transfer impetus, expressed by the concentration difference. The main parameters of the model are the mass transfer coefficient, the carrier gas flow rate and the concentration of H2S in liquid phase. The results showed that the model can simulate and predict H2S emission concentrations of various processes in WWTPs. Moreover, the model can analyze and predict the influences of different pH values, mass transfer coefficients and carrier gas flow rates on H2S emission concentrations and loads. Therefore, the model provides theoretical guidance for design of WWTPs regarding H2S emissions.Implications: Modeling and prediction of H2S emission from wastewater are quite important since gaseous H2S will induce significant corrosion and odor problems. Most of previous studies are focused on H2S emission from wastewater in pipeline system, which may not be fit for H2S emission in wastewater treatment plants (WWTPs). Thus in this study, a model for predicting H2S emission from typical units of WWTPs is established and verified. Moreover, the influences of pH values, mass transfer coefficients and carrier gas flow rates on H2S emission are analyzed. The model can be a useful tool to predict the H2S concentration in odor gas collection system of WWTP and understand the behaviors of H2S emission under different WWTPs operating conditions.
Assuntos
Poluentes Atmosféricos , Purificação da Água , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Odorantes/análise , Eliminação de Resíduos Líquidos , Águas Residuárias/análiseRESUMO
OBJECTIVE: To discuss the feasibility of estimating energy consumption of green laser in photoselective vaporization of prostate (PVP) based on the preoperative volume of prostate. METHODS: From January 2005 to January 2007, 260 patients with benign prostatic hyperplasia (BPH) had been treated with PVP. Preoperative prostatic volume and post-two-weeks-operative prostatic volume of each patient were measured by transrectal ultrasound (TRUS). Energy consumption and emission time of green laser were recorded during the operation. Then we calculated the amount of energy consumption needed in vaporizing one gramme prostatic tissue, evaluated the correlation of energy consumption and preoperative volume of prostate by means of correlation-regression analysis, and established its regression equation. RESULTS: The amount of energy consumption needed in vaporizing one gramme prostatic tissue was (6.9 ± 0.6)kJ. The correlation of energy consumption and preoperative volume of prostate was significantly positive linear correlated. Its regression equation was: Energy Consumption (kJ) = 4.7 x Preoperative Volume of Prostate (cm³) - 14.1. CONCLUSION: It is feasible to estimate energy consumption of green laser in PVP based on preoperative volume of prostate.
Assuntos
Próstata/patologia , Hiperplasia Prostática/cirurgia , Ressecção Transuretral da Próstata/métodos , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Humanos , Terapia a Laser , Masculino , Pessoa de Meia-Idade , Hiperplasia Prostática/patologiaRESUMO
OBJECTIVE: The purpose of this study was to determine the values of the hemodynamic parameters of Doppler sonography in the diagnosis of renal artery stenosis (RAS) (diameter reduction >/=50%) and to investigate their possible influencing factors. METHODS: Five Doppler parameters, including renal peak systolic velocity (RPSV), renal-aortic ratio (RAR), renal-renal ratio (RRR), renal-segmental ratio (RSR), and renal-interlobar ratio (RIR), were measured in 81 patients before arteriography. Arteries with >/=50% diameter reduction were considered stenosed at renal arteriography. Receiver operating characteristic curve analysis was performed to determine the optimal parameters. The sensitivity, specificity, positive and negative predictive values, and accuracy at various threshold values were calculated. RESULTS: Sixteen accessory renal arteries (15 normal, one mild stenosis) were identified at arteriography. Of the 153 main renal arteries demonstrated at arteriography, 79 were normal or demonstrated stenosis <50%, 68 demonstrated moderate stenosis (50%-99%), and 6 demonstrated total occlusion. Doppler sonographic examination was technically successful in 91.7% (154/168) of main and accessory renal arteries. The optimal threshold values of RPSV, RAR, RRR, RSR, and RIR were 170 cm/s, 2.3, 2.0, 4.0, and 5.5, respectively. The parameters RPSV, RSR, and RIR showed good diagnostic results with accuracies equal to or greater than 88%, whereas RAR and RRR presented a sensitivity of only 76.47%. The diagnostic accuracies of RPSV, RAR, and RRR were approximately 3% higher after exclusion of the eight patients with abdominal aorta stenosis. CONCLUSION: It should be feasible and necessary to measure three representative hemodynamic parameters (RAR, RPSV, and RIR or RSR) in the diagnosis of >/=50% RAS. The PSVs in the abdominal aorta and renal artery can be affected by factors other than RAS, which may decrease the accuracy of RAR. However, post-PSV ratios are minimally affected by PSV in the abdominal aorta or by an equal proportional change in PSVs in the renal artery trunk and its intrarenal renal arteries; therefore, use of post-PSV ratios dramatically overcomes some limitations of RAR.
Assuntos
Hemodinâmica/fisiologia , Obstrução da Artéria Renal/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Adolescente , Adulto , Idoso , Angiografia/métodos , Área Sob a Curva , Velocidade do Fluxo Sanguíneo/fisiologia , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Probabilidade , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Resistência Vascular/fisiologiaRESUMO
OBJECTIVE: To investigate the expression of metastasis suppressor gene KAI1 in cervical carcinoma and the impact of human papillomavirus 16 E6, E7, 18 E6/E7 infection on the expression of KAI1. METHODS: The expressions of KAI1 protein in the formalin-fixed, paraffin-embedded specimens of 20 normal cervical epthelium, 15 cervical in situ carcinoma and 70 primary invasive cervical carcinoma were detected by immunohistochemistry SP. Polymerase chain reaction (PCR) tests were also undertaken to detect the HPV16 E6, E7 and HPV18 E6/E7 DNA. RESULTS: The expression of KAI1 protein was down-regulated in the invasive carcinoma and in situ carcinoma compared with the controls (P < 0.05). No significant difference was found in the expression of KAI1 protein between invasive carcinoma and in situ carcinoma. The infections of HPV16 E6, E7 and HPV18 E6/E7 were found in 67.1%, 54.3% and 12.9% of the invasive carcinoma, respectively. However, there was no correlation between the expression of KAI1 and the infections of HPV16 E6, E7 and HPV18 E6/E7. CONCLUSION: The expression of KAI1 protein is down-regulated in cervical carcinoma, which is not associated with the infection of HPV16 E6, E7 and 18 E6/E7.
Assuntos
Proteínas de Ligação a DNA/genética , Proteína Kangai-1/biossíntese , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/patologia , Proteínas Repressoras/genética , Neoplasias do Colo do Útero/patologia , Adulto , Idoso , DNA Viral/análise , DNA Viral/genética , Eletroforese em Gel de Ágar , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/virologiaRESUMO
OBJECTIVE: To explore the effect of metastasis suppressor gene KAI1 on the proliferation and invasive ability of cervical cancer cell line CaSki. METHODS: pCMV-KAI1 cDNA plasmid was transferred into cervical carcinoma cell line CaSki by liposome, which had low level of endogenous KAI1 expression. The expressions of KAI1 protein and mRNA were determined by immunohistochemistry and real-time fluorescence quantitative PCR (RT-PCR), the proliferation of KAI1-transfected CaSki cells was investigated by MTT assay and the invasive ability of these cells was evaluated by in vitro invasion assays. RESULTS: After the transfection of pCMV-KAI1 cDNA, the level of KAI1 mRNA and protein expression in CaSki cell were increased (P < 0.05), while the cell proliferation was suppresssed, and the migrative ability of passing through the membrane filte also decreased evidently (P < 0.05). CONCLUSION: The KAI1 metastasis suppressor gene suppressed the ability of proliferation and invasion of cervical cancer cell CaSki in vitro.
Assuntos
Proliferação de Células , Proteína Kangai-1/genética , Neoplasias do Colo do Útero/genética , Feminino , Genes Supressores de Tumor/fisiologia , Humanos , Proteína Kangai-1/biossíntese , Invasividade Neoplásica , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/patologiaRESUMO
OBJECTIVE: To isolate human hemoglobin and its fragrments, compare their antimicrobial activity in vitro and pilot study of their antimicrobial activity in vivo. METHODS: The alpha and beta chains of hemoglobin were separated by cation exchange chromatography and gel chromatography; The alpha and beta chains were cleaved by cyanogens bromide respectively. The cleaved fragments were purified by reverse phase high performance liquid chromatography. Antimicrobial activity of hemoglobin and its fragments was determined by agrose radial diffusion assay. After establishment of E. coli vaginal infection model, the rats were randomized into the experimental group (hemoglobin group) and the control group. The histologically pathological section was observed. RESULTS: Hemoglobin, alpha/beta chain and their fragments had similar antibacterial activities in vitro, which were mainly against Gram-negative bacteria E. coli; except alpha1-32 had a comparatively lower activity. Antimicrobial activity in vivo: a comparison of the hemoglobin group with the matrix control group (no treatment after infection), the surface layer of vaginal stratified squamous epithelium was smoother, inflammatory cells were significantly reduced in the lamina propria and congestion was obviously decreased. CONCLUSION: Human hemoglobin and its fragments had antibacterial activity in vitro, hemoglobin might relieve the inflammation of E. coil vaginal infection in rats moreover.
Assuntos
Antibacterianos/farmacologia , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli/efeitos dos fármacos , Hemoglobinas/farmacologia , Fragmentos de Peptídeos/farmacologia , Animais , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Infecções por Escherichia coli/microbiologia , Feminino , Hemoglobinas/química , Humanos , Fragmentos de Peptídeos/isolamento & purificação , Pseudomonas aeruginosa/efeitos dos fármacos , Distribuição Aleatória , Ratos , Ratos Wistar , Vagina/efeitos dos fármacos , Vagina/microbiologiaRESUMO
Nitrogen (N) is an important element for plant growth in terrestrial ecosystems. Studying soil N cycling is crucial for understanding the structures and functions of an ecosystem. However, our knowledge of soil N dynamics in karst regions is still limited. In addition, while China's karst regions have conducted a series of vegetation restoration projects, the vegetation restoration effects on soil N pathways are still largely unknown. Therefore, this study selected four typical ecosystems representing four main vegetation restoration stages (i. e., cropland, grassland, shrubland, and forest) in a karst region in Huanjiang Province, southwest China. In these ecosystems, soil N pathways, including net ammonization rate (net ammonization, fungal ammonization, and bacterial ammonization), net nitrification rate (i. e., net nitrification, heterotrophic nitrification, autotrophic nitrification, fungal nitrification, and bacterial nitrification), net N mineralization rate (net N mineralization, fungal mineralization, and bacterial mineralization), and soil properties were measured. Our results showed that nitrification rate was high in all ecosystems, but the ammonization rate was low, resulting in nitrite being the main inorganic N form in karst soil. Autotrophic and heterotrophic nitrification rates accounted for 80% and 20% of the net nitrification rate, respectively. After the addition of fungal and bacterial inhibitors, ammonization rates increased for all treatments, but the nitrification rates decreased. Following vegetation restoration, soil N mineralization and nitrification rates all increased, but the ammonization rates significantly decreased. This pattern was significantly correlated with soil organic carbon, total nitrogen, nitrate, microbial biomass, and the activity of N-acquisition enzymes in these ecosystems. Our findings provide very useful information for understanding soil N cycling in the karst regions.
Assuntos
Ecossistema , Nitrificação , Nitrogênio/análise , Solo/química , China , Fazendas , Florestas , Pradaria , PlantasRESUMO
Fetal adducted thumbs have been described in association with hydrocephalus and other abnormalities, but in cases without other structural malformations the determination of prognosis and recurrence risk is challenging. The aim of our study is to analyze the characteristics, natural history, and postnatal outcome of such cases.A retrospective study was conducted over a period of 4 years in a tertiary referral center. All fetuses diagnosed as adducted thumbs without other structural malformations comprised the study group. Prenatal sonographic features and neonatal outcome are documented.There were 4 cases of fetal adducted thumbs diagnosed during the study period. No cases demonstrated other structural malformations throughout the gestation. A smaller head was noted in 2 cases during the follow-up, and all cases presented with polyhydramnios on the first or ensuing scans. Three cases died after birth due to swallowing or breathing difficulty, and the surviving 1 showed convulsion and mental retardation.Fetal adducted thumb might be an early and specific sonographic marker of impaired neurodevelopment. Close follow-up and genetic investigation should be performed in these cases. Ultrasound examination plays an important role in the prenatal diagnosis and counseling of cases without detailed prenatal genetic analysis.
Assuntos
Feto/diagnóstico por imagem , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico por imagem , Deformidades da Mão/diagnóstico por imagem , Deficiência Intelectual/diagnóstico por imagem , Transtornos do Neurodesenvolvimento/diagnóstico por imagem , Diagnóstico Pré-Natal/instrumentação , Paraplegia Espástica Hereditária/diagnóstico por imagem , Polegar/anormalidades , Polegar/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Variações do Número de Cópias de DNA/genética , Feminino , Feto/anormalidades , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/mortalidade , Idade Gestacional , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual/mortalidade , Imageamento por Ressonância Magnética/métodos , Masculino , Poli-Hidrâmnios/diagnóstico por imagem , Gravidez , Estudos Retrospectivos , Paraplegia Espástica Hereditária/genética , Paraplegia Espástica Hereditária/mortalidade , Polegar/patologiaRESUMO
Annually a tremendous amount of office waste paper (OWP) is discarded creating environmental pollution. Therefore, how to make this paper from waste to wealth and use it in new approaches have become a meaningful and challenging work. In this work, OWP being a cellulose rich biomass was employed for the production of cellulose nanocrystals (CNCs) by acid hydrolysis with different acid concentrations but without subjecting OWP to alkali and bleaching treatments. The testing results showed that CNCs prepared using sulfuric acid concentration of 59% with respect to OWP had the highest crystallinity and this concentration was the transition concentration for the production of opaque CNCs film with convoluted nanofibers to transparent one with orientated nanofibers. Besides, CNCs prepared using acid concentration of 65% coated on PET sheet not only had a better water vapor barrier property but also was on a par with the transparency of PET, which was hopeful to be used as coating materials in packaging materials.
RESUMO
In order to help mitigate widespread cadmium (Cd) and arsenic (As) co-contamination in paddy soils in China, screening and breeding of low-accumulating rice (Oryza sativa L.) cultivars (excluders) have been widely adopted. However, the performance of rice cultivars for grain Cd and As accumulation may vary in different growing environments. The inability to identify stable low-accumulating cultivars has largely hindered their application. In this study, 51 rice cultivars were evaluated at four Cd- and As-contaminated paddy sites in two crop seasons in northern Guangdong Province, China. The aim was to investigate the effects of cultivar, environment and their interactions in determining grain Cd and As concentrations, and so to identify stable low-accumulating cultivars. Results showed that environment effects dominated the Cd and As concentrations in rice grains, explaining 87% of the total variations. The crop season played a vital role; compared to early season, grain Cd levels increased and As levels lowered significantly in late season. Large variations in grain Cd, total As, inorganic As concentrations and the percentage of inorganic As were observed between different cultivars. Conventional japonica cultivars exhibited lower Cd levels but higher As levels in the grains than did indica cultivars. The cultivarâ¯×â¯environment interaction (CEI) was significant, and its importance was comparable to the cultivar effect. By measuring and interpreting such an interaction, stable Cd and As excluder cultivars were identified based upon the yield, grain Cd and As levels as well as the stabilities of cultivars across the trial environments. Two stable Cd and As co-excluders were found among the hybrid indica cultivars. These results demonstrated that the variations in grain Cd and As concentrations could mainly be attributed to the environment effects and cultivar selection practices should include the analysis of CEI to identify stable low-accumulating rice cultivars.