[Inversion of Water Quality Parameters Based on UAV Multispectral Images and the OPT-MPP Algorithm].

Unmanned aerial vehicle (UAV) multispectral remote sensing can be used to monitor multiple water quality parameters, such as suspended solids, turbidity, total phosphorus, and chlorophyll. Establishing a stable and accurate water quality parameter inversion model is a prerequisite for this work. The matching pixel-by-pixel (MPP) algorithm is an inversion algorithm for high resolution features of UAV images; however, it is associated with problems of excessive computation and over-fitting. To overcome these problems, the optimize-MPP (OPT-MPP) algorithm is proposed. In this study, Qingshan Lake in Hangzhou City, Zhejiang Province, was used as the research area. Forty-five samples were collected to construct the OPT-MPP algorithm inversion model for two water quality parameters:the suspended sediments concentration (SS) and turbidity (TU). The results showed that the optimal suspended sediment concentration inversion model had a determination coefficient (R2) of 0.7870 and a comprehensive error of 0.1308. The optimal turbidity inversion model had a R2 of 0.8043 and a comprehensive error of 0.1503. Hence, the inversion of the spatial distribution information for water quality parameters in each experimental area of QingShan Lake was realized by using the optimal models of the two established parameters.

A data-driven noise reduction method and its application for the enhancement of stress wave signals.

Ensemble empirical mode decomposition (EEMD) has been recently used to recover a signal from observed noisy data. Typically this is performed by partial reconstruction or thresholding operation. In this paper we describe an efficient noise reduction method. EEMD is used to decompose a signal into several intrinsic mode functions (IMFs). The time intervals between two adjacent zero-crossings within the IMF, called instantaneous half period (IHP), are used as a criterion to detect and classify the noise oscillations. The undesirable waveforms with a larger IHP are set to zero. Furthermore, the optimum threshold in this approach can be derived from the signal itself using the consecutive mean square error (CMSE). The method is fully data driven, and it requires no prior knowledge of the target signals. This method can be verified with the simulative program by using Matlab. The denoising results are proper. In comparison with other EEMD based methods, it is concluded that the means adopted in this paper is suitable to preprocess the stress wave signals in the wood nondestructive testing.

Stress wave signal denoising using ensemble empirical mode decomposition and an instantaneous half period model.

Stress-wave-based techniques have been proven to be an accurate nondestructive test means for determining the quality of wood based materials and they been widely used for this purpose. However, the results are usually inconsistent, partially due to the significant difficulties in processing the nonlinear, non-stationary stress wave signals which are often corrupted by noise. In this paper, an ensemble empirical mode decomposition (EEMD) based approach with the aim of signal denoising was proposed and applied to stress wave signals. The method defined the time interval between two adjacent zero-crossings within the intrinsic mode function (IMF) as the instantaneous half period (IHP) and used it as a criterion to detect and classify the noise oscillations. The waveform between the two adjacent zero-crossings was retained when the IHP was larger than the predefined threshold, whereas the waveforms with smaller IHP were set to zero. Finally the estimated signal was obtained by reconstructing the processed IMFs. The details of threshold choosing rules were also discussed in the paper. Additive Gaussian white noise was embedded into real stress wave signals to test the proposed method. Butterworth low pass filter, EEMD-based low pass filter and EEMD-based thresholding filter were used to compare filtering performance. Mean square error between clean and filtered stress waves was used as filtering performance indexes. The results demonstrated the excellent efficiency of the proposed method.

Hemogram and bone marrow morphology in children with chronic aplastic anemia and myelodysplastic syndrome.

BACKGROUND: Aplastic anemia (AA) and myelodysplastic syndrome (MDS) are both acquired disorders in which bone marrow fails to produce or release sufficient blood cells. Anemia, infections and thrombocytopenia are common signs of such diseases. Clinically, it is difficult to distinguish chronic aplastic anemia (CAA) from MDS, especially from MDS without splenomegaly. As prognosis and treatment of AA and MDS are different, it is extremely important to make a differential diagnosis for the two diseases. METHODS: The medical records of 31 patients with CAA and 17 patients with MDS were retrospectively reviewed. Hemogram, bone marrow smear and biopsy for those patients were analyzed. RESULTS: The mean counts of monocytes and platelets in the peripheral blood of the CAA patients were significantly lower than those of the MDS patients. Bone marrow smear showed a reduction of cellularity in CAA patients. The mean counts of myeloblasts+promyelocytes, myeloblasts+proerythroblasts, and megakaryocytes in the bone marrow of CAA patients were markedly lower than those in MDS patients. But the mean lymphocyte count was reversed. Bone marrow cells showed morphological abnormalities in MDS. Hematopoietic tissue in the bone marrow biopsy decreased obviously in more than 96% of the patients with CAA. Adipose tissue in the bone marrow of CAA patients increased obviously. A reduction or deficiency (<2 cell/piece) of megakaryocytes was noted in 28 patients with CAA. Fibrous tissue in the bone marrow was detected in 5 patients with CAA. Bone marrow biopsy results showed hypercellular changes in 12 MDS patients. Ten patients showed aggregated erythroblasts which were in the same stage of development, and 15 patients had abnormal localization of immature precursors (ALIP). CONCLUSIONS: Blood cell counts can be decreased in addition to the reduction of cellularity in the bone marrow without dyshematopoiesis in CAA patients. Peripheral blood monocytes, fibrous tissue and cellularity in bone marrow are increased in MDS. Dyshematopoiesis and ALIP may appear characteristically in the children with MDS. Histology of bone marrow is important in the differential diagnosis of MDS and CAA.

[The value of multiparameter flow cytometry in diagnosis of lymphocytic leukemia and bone marrow involvement of non-Hodgkin's lymphoma].

BACKGROUND & OBJECTIVE: Lymphocytic leukemia and bone marrow involvement of non-Hodgkin's lymphoma (NHL) can be diagnosed by bone marrow morphology or lymph node biopsy combined with bone marrow examination. The data of original and differentiation status of tumor can be analyzed by immunophenotype of bone marrow. These are necessary for diagnosis and treatment of lymphocytic malignancy. This study was designed to investigate the value of multiparameter flow cytometry in diagnosis of leukemia and bone marrow involvement of NHL. METHODS: The samples from 11 cases of untreated leukemia bone marrow and 41 cases of untreated NHL with bone marrow involvement and 2 cases of bone marrow whose biopsy could not be obtained due to huge mass in mediastinum and abdomen were detected by multiparameter flow cytometry using antibodies of T, B, Myeloid cell series. Three-color staining was done by CD45 combined with two cell series or special phase antibodies. Using CD45/SSC set gate to identify blast cells from mature cells. The samples were analyzed using five parameters [forward scatter (FSC), side scatter(SSC), McAb1-FITC, McAb2-PE, and CD45-cychrome]. RESULTS: Immunophenotype and diagnosis of 11 cases of leukemia were further confirmed by flow cytometry (FCM). Of 41 cases of NHL with bone marrow involvement, 33 cases (80.5%) lymph nodes immunophenotype by pathology diagnosis were consistent with bone marrow immunophenotype by FCM, 8 cases (19.5%) were inconsistent, but right diagnosis were made by combining with clinical presentation, pathology, bone marrow morphology and FCM. Another 2 cases with huge mediastinal mass and abdominal mass were diagnosed as T-NHL and B-NHL by bone marrow morphology and FCM without lymph node biopsy. CONCLUSION: Multiparameter flow cytometry of bone marrow can further ascertain the diagnosis of leukemia and NHL with bone marrow involvement. It also gives us data of cells lineage and differentiation status for leukemia and NHL. It is helpful for diagnosis, differential diagnosis, and treatment.

[Expression and clinical significance of mdr-1 gene in lymphoma].

BACKGROUND & OBJECTIVE: It is still unclear whether overexpression of mdr-1 gene play a role in the chemotherapy resistance of lymphoma. This study was designed to investigate P-glycoprotein(P-gp) and mdr-1 mRNA levels of lymphoma and to observed the impact of P-gp level upon chemotherapy response. METHODS: Ten samples of relapsed lymphoma and 21 samples of untreated lymphoma were assessed by flow cytometry(FCM). The mdr-1 mRNA levels were determined by real-time reverse-transcription PCR assay simultaneously in eighteen samples. The impact of P-gp levels upon chemotherapy response was observed in seventeen patients. RESULTS: Nineteen Percent (4/21) patients overexpressed P-gp at diagnosis as compared to 60%(6/10) in relapse(P = 0.012). The copy numbers of mdr-1 mRNA were 4 x 10(2)-1.32 x 10(4) copies/microgram RNA in untreated group and 4 x 10(2)-4 x 10(4) copies/microgram RNA in recurrent group. There existed significant difference in the distribution of mdr-1 mRNA expression between these two groups, P < 0.05. The complete response rates were 46% (6/13) in P-gp non-overexpression group and 25% (1/4) in P-gp overexpression group(P = 0.60). CONCLUSION: Relapsed lymphomas highly express P-gp and mdr-1 mRNA. The overexpression of mdr-1 gene may play a role in the multidrug resistance of relapsed lymphoma.

[A method to detect gene transfection efficacy by flow cytometry].

BACKGROUND & OBJECTIVE: Analysis of gene transfer and expression is conventionally inferred from the percentage of positive cells expressing reporter gene in total cells, referred as transfection rate, by investigators counting under a microscope or fluoroscope, which was called as manual counting. But in many cases, it is not accurate and easily influenced by the subjectivity of observer. This study was designed to seek a convenient method to assess objectively and accurately the efficacy of gene transfer and expression. METHODS: Hepatocellular carcinoma(HCC) HepG2 cells were infected with a recombinant adenovirus expressing green fluorescent protein(AdCMV/GFP) at a series of multiplicities of infection(MOIs). 24 h later, the transfection rates were assessed by manual counting under fluorescent microscope. Meanwhile, besides transfection rates, fluorescent indices(FIs) which indicated the efficiency of gene transfer and expression were analyzed by flow cytometry (FCM). Transfection efficiencies of AdCMV/GFP to HCC Hep3B, Bel7402, SMMC7721 cells and nasopharyngeal carcinoma CNE-2 cells were also tested by FCM. RESULTS: Although transfection rates by FCM were slightly higher than that by manual counting, both were logarithmic correlative with vector doses. The stirring was that FIs by FCM showed compellent linear correlation with vector doses (r = 0.9984, P < 0.001). The efficiency of gene transfer in other cells by FCM were similar to that in HepG2. CONCLUSION: The efficiency of gene transfer and expression in mammalian cells can be easily analyzed by flow cytometry, which is more sensitive, objective, and accurate than manual counting, especially in assessing the efficiency of multiple gene transfer (multi-copies per cell) and expression.