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Context Few iodine balance studies have been conducted in school-age children. Objective This study aimed to conduct an iodine balance study in school-age children. Methods We measured daily iodine intake, excretion, and retention for 3 consecutive days without any dietary interventions in school-age children. Linear mixed-effects models were used to fit the relationship between total iodine intake and iodine retention. Results 29 children aged 7-12 years (mean age 10.2 ± 1.4 years) with normal thyroid function and thyroid volume were recruited. The 0 balance value (iodine intake = iodine excretion, iodine retention = 0 μg/day) shifted with iodine intake in an iodine sufficient population. The 0 balance value for school-age children with an iodine intake of 235 (133, 401) μg/day is 164 μg/day. Children aged 7-12 years with iodine intake >400 μg/day were almost all in a positive iodine state. Conclusion An iodine intake of 235 (133, 401) μg/day for children aged 7-10 years achieved a 0 balance value of 164 μg/day. Long-term iodine intake of >400 μg/day is not recommended.

Ensuring optimal iodine nutrition in pregnant women is a global public health concern. However, there is no direct data on safe tolerable upper intake levels (ULs) for pregnant women. A cross-sectional study was performed to determine the ULs of pregnant women. A total of 744 pregnant women were enrolled in this study. The median (IQR) urinary iodine concentration (UIC) in pregnant women was 150.2 (87.6, 268.0) μg/L, and the urinary iodine excretion (UIE) over 24 h was 204.2 (116.0, 387.0) μg/day. Compared with those with a UIE figure of between 150–250 μg/day, the reference group, the prevalence of thyroid dysfunction was 5.7 times higher (95%CI: 1.7, 19.2) in pregnant women with a UIE figure of between 450–550 μg/day, and 3.9 times higher (95%CI: 1.5, 10.3) in pregnant women with a UIE figure of ≥550 μg/day. Compared with an estimated iodine intake (EII) of between 100–200 μg/day, the reference group, the prevalence of thyroid dysfunction was 4.3 times higher (95%CI: 1.3, 14.4) in pregnant women with a UIE figure of between 500–600 μg/day, and 3.6 times higher (95%CI: 1.5, 8.9) in pregnant women with UIE of ≥600 μg/day. In general, our cross-sectional study found that excessive iodine intake during pregnancy appears to directly increase the risk of thyroid dysfunction. Avoiding chronic iodine intakes of 500 μg/day or higher or having a UIE figure of ≥450 μg/day is recommended for pregnant women in China.

PURPOSE There is some uncertainty about the optimal ranges for urinary iodine concentration (UIC) during pregnancy. This study aimed to explore associations between maternal UIC and thyroid function in iodine sufficient and mildly iodine deficient areas. METHODS It was a cross-sectional study in which 1461 healthy pregnant women were enrolled to collect their blood and urine samples during their routine antenatal care in Tianjin and Wuqiang, China. Wuqiang was a mildly iodine-deficient region, while Tianjin was iodine sufficient. UIC, free triiodothyronine (FT3), free thyroid hormone (FT4), thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), serum iodine concentration (SIC) including total serum iodine concentration (tSIC) and non-protein bound serum iodine concentration (nbSIC) were assessed during the routine antenatal care visits. RESULTS The median UIC in pregnant women was 174 (113, 249) μg/L in Tianjin and 111 (63, 167) μg/L in Wuqiang, respectively. Compared with Tianjin, UIC, FT3 and TSH were lower, and FT4, tSIC, nbSIC, rates of TPOAb and TgAb positivity and the thyroid dysfunction rate (TDR) were higher in Wuqiang (P

The relationship between serum iodine and thyroid dysfunctions in male and female adults is poorly understood. This study aimed to explore the relationship between serum and urine iodine and thyroid dysfunction in male and female adults. A total of 1320 participants were included in the final analysis. We collected basic demographic information, as well as blood and spot urine samples, to determine serological indices and iodine nutritional status of subjects. The median (IQR) of UIC, UIC/UCr, SIC were 155.8 (94.5, 211.1) µg/L, 138.1 (91.1, 207.6) µg/g and 70.6 (59.8, 83.9) µg/L, respectively. SIC was positively correlated with UIC and UIC/UCr (P P P = 0.02, P = 0.002). In male subjects, subjects with SIC༞97.1 µg/L had a higher risk of hyperthyroidism (OR = 2.91, 95% CI: 1.38, 6.19) and overt hypothyroidism (OR = 5.59, 95% CI: 1.88, 6.42). In female subjects, subjects with SIC

To evaluate residents in North China cognition level of iodine nutrition and their intention to evaluate individual iodine status.From February 2019 to June 2020, randomly selected six provinces and cities in north China and more than three cities or areas, then randomly selected local investigators and distributed questionnaires to urban and rural residents. The questionnaire was divided into three parts: basic information, iodine nutrition knowledge, iodine status evaluation demand and approaches.Finally, there are 740 questionnaires were included. The scores of iodine knowledge of the subjects were generally low, about 71.22% of the subjects with less than 6 points(full score of 12 points). Residents who did not know how to choose the type of salt accounted for 25.14%. Provinces and cities with low utilization rate of iodized salt(Tianjin, Shandong) had higher requirements for salt use guidance and iodine status evaluation. The awareness rate of the subjects to the harm of iodine deficiency was low(34.46%), especially the hazard to pregnant women and infants(7.57%, 4.59%). Subjects had a high demand for using wechat mini-program or kit to evaluate individual iodine nutrition(87.45%, 89.39%).At present, residents in North China have a low cognitive level of iodine nutrition, which lead to them the doubts when choosing salt types. The selection of iodized salt can be effectively guided by propagating iodine nutrition knowledge and promoting accurate iodine nutrition evaluation.

Summary Background Saliva iodine concentration (SIC) has been found to be a good indicator of iodine nutritional status. However, limited information is available regarding saliva iodine characteristics. Aims The study aimed to evaluate intra-day, intra-individual, and population SIC variation in order to provide information on optimal sample size and sampling time for assessing iodine nutritional status. Methods Twenty-nine healthy school-aged students were recruited. Iodine intake from diet and water, and iodine excretion through urine and feces were assessed over a three-day period. Saliva samples were collected six times a day. Results Diurnal variations were observed in SIC corresponding to iodine intake. The mean CV in SIC was lower than that for 24-hour urinary iodine concentration (24-h UIC) and 24-hour urinary iodine excretion (24-h UIE) not only at the individual level (42.73% vs. 47.71% and 49.69%) but also at the population level (71.29% vs. 100.43% and 72.49%). The number of saliva samples needed to estimate the iodine level with 95% CI within precision ranges of ±10%, ±20% was 55, 14 in an individual, and 180, 45 in a population. There was a good correlation between post-lunch SIC and total daily iodine intake. Conclusions Saliva iodine has utility for evaluating the recent iodine nutrition of individuals and populations. The variation in SIC was lower than that for 24-h UIC and 24-h UIE. Saliva may be preferred over urine because of its ease of collection. Fourteen samples are needed to assess individual iodine status and forty-five saliva samples for assessment of population iodine status with reasonable precision. We recommend that saliva samples be collected after 14:00 in a day.

Background The relationship between low serum iodine and thyroid dysfunctions in adults is not well understood. This study aimed to explore the relationship between serum and urinary iodine and thyroid dysfunctions in the adult population. Methods: A total of 1320 participants were included in the final analysis. We collected basic demographic information, as well as blood and spot urine samples, to determine serological indices and iodine nutritional status of subjects. Results: The median (IQR) serum iodine (SI) level was 70.5µg/L (59.6–83.6µg/L). Compared to those with 59.6µg/L ≤ SI P = 0.02) was significantly higher than that of sUIC/UCr (0.446, P = 0.005). Conclusions: Serum iodine is more sensitive than urine iodine in the diagnosis of thyroid dysfunctions. Low serum iodine concentration is associated with an increased risk of thyroid dysfunctions, especially hypothyroidism.

The relationship between serum iodine (SIC) and thyroid dysfunctions in adults is poorly understood, and this study aimed to explore their relationship. A total of 1320 participants were included in the final analysis. We collected basic demographic information, blood, and spot urine samples to determine serological indices and iodine nutritional status. The median (IQR) of urinary iodine (UIC)/urinary creatinine (UCr), UIC, SIC were 138.1 (91.1, 207.6) μg/g, 155.8 (94.5, 211.1) μg/L, and 70.6 (59.8, 83.9) μg/L, respectively. The 90% reference ranges for UIC/UCr and SIC were 66.5-349.8 mg/g and 49.3-97.1 μg/L. SIC was positively correlated with UIC and UIC/UCr. The prevalence of overt hypothyroidism and subclinical hypothyroidism in female was significantly higher than that in male (P = 0.02, P = 0.002). In male, subjects above the upper reference value of SIC (97.1 μg/L) had a higher risk of subclinical hyperthyroidism (OR = 4.46, 95% CI: 1.29, 12.8) and overt hypothyroidism (OR = 5.59, 95% CI: 1.88, 6.42). In female, subjects below the lower reference value of SIC (49.3 μg/L) had a higher risk of overt hypothyroidism (OR = 2.18, 95% CI: 1.10, 4.06), TgAb positive (OR = 1.97, 95% CI: 1.15, 3.32) and TPOAb positive (OR = 2.48, 95% CI: 1.41, 4.26). In conclusion, serum iodine can be used as an indicator to evaluate iodine nutritional status and thyroid dysfunctions. Higher serum iodine concentration was associated with an increased risk of subclinical hyperthyroidism and overt hypothyroidism in men; lower serum iodine concentration was associated with an increased risk of overt hypothyroidism and positive TgAb and TPOAb in women.

Objectives: The reference values for thyroid volume (Tvol) determined by ultrasound require supportive data of normal Tvol from local iodine-sufficient populations. This study aimed to explore new reference values for Tvol in Chinese adults and comprehensively evaluate the factors associated with enlarged Tvol. Methods: A cross-sectional study was conducted in Tianjin, China. Tvol was measured by ultrasound in adults with long-term iodine sufficiency. Blood and urine samples were collected to evaluate biochemical indexes, thyroid function, and iodine status. Results: A total of 1,991 adults from the urban and suburban areas were analysed. The trend of Tvol increasing with age was observed in men under age 40 years and in women under age 52 years. In the quantile regression analyses, we found that body surface area (BSA) (β = 7.22, 95% CI: 5.33, 9.12), thyroid-stimulating hormone (TSH) (β = −1.48, 95% CI: −2.39, −0.57), thyroid nodules (TNs) (β = 6.70, 95% CI: 2.19, 11.22), and metabolic syndrome (MetS) (β = 1.40, 95% CI: 0.63, 2.17) had a strong effect on Tvol at higher percentiles in males. The dominant factors influencing Tvol were BSA (β = 9.64, 95% CI: 2.66, 16.61), TSH (β = −0.78, 95% CI: −1.16, −0.39), and TNs (β = 1.11, 95% CI: 0.43, 1.79) in females. The largest reference values for Tvol based on BSA were 20.18 (17.79, 24.32) mL in males and 15.31 (14.05, 16.70) mL in females. Conclusions: Quantile regression analyses showed that a high BSA index, a decreased TSH level, and the prevalence of TNs were essential factors associated with the enlargement of the thyroid gland. Our findings reported the new reference values for Tvol determined by ultrasound based on gender and BSA in Chinese adults.

This paper develops a new biased estimator—generalized ridge and principal correlation (GRPC) estimator of the regression coefficient in the growth curve model. The properties of the proposed estimator are shown to be superior to those of least squares (LS) estimator, principal correlation estimator, principal component estimator, and generalized ridge and principal component estimator in terms of both the mean squared error (MSE) and Pitman closeness (PMC). Moreover, a numerical study on synthetic data has been performed to demonstrate the optimality of the proposed estimator.

We aimed to explore the genotypic and phenotypic characteristics of neonatal-onset inflammatory bowel disease (IBD) with combined immunodeficiency due to

Iodine intake and excretion vary widely; however, these variations remain a large source of geometric uncertainty. The present study aims to analyse variations in iodine intake and excretion and provide implications for sampling in studies of individuals or populations. Twenty-four healthy women volunteers were recruited for a 12-d sampling period during the 4-week experiment. The duplicate-portion technique was used to measure iodine intake, while 24-h urine was collected to estimate iodine excretion. The mean intra-individual variations in iodine intake, 24-h UIE (24-h urinary iodine excretion) and 24-h UIC (24-h urinary iodine concentration) were 63, 48 and 55 %, respectively, while the inter-individual variations for these parameters were 14, 24 and 32 %, respectively. For 95 % confidence, approximately 500 diet samples or 24-h urine samples should be taken from an individual to estimate their iodine intake or iodine status at a precision range of ±5%. Obtaining a precision range of ±5% in a population would require twenty-five diet samples or 150 24-h urine samples. The intra-individual variations in iodine intake and excretion were higher than the inter-individual variations, which indicates the need for more samples in a study on individual participants.

The effects of metabolic syndrome (MetS) on thyroid nodules (TN) and thyroid volume (TV), especially the related gender and age disparities, are controversial. In this study, we aimed to assess the relationships between MetS and TN and TV in an adult population. This cross-sectional study was performed in an adult population in Tianjin. A total of 2606 subjects were enrolled. TV and TN were measured by thyroid ultrasonography. Blood samples were collected to measure biochemical and metabolic parameters. The prevalence of TN was significantly higher in the MetS (+) group than in the MetS (−) group (P

This research aimed to investigate the compensation mechanism of iodine deficiency and excess in the mammary gland during lactation. Female rats were divided into the low iodine group (LI), the normal iodine group (NI), the 10-fold high iodine group (10HI) and the 50-fold high iodine group (50HI). We measured the iodine levels in the urine, blood, milk, and mammary gland. The protein expression of sodium/iodide symporter (NIS), DPAGT1, and valosin-containing protein (VCP) in the mammary gland was also studied. The 24-hour urinary iodine concentration, serum total iodine concentration, serum non-protein-bound iodine concentration, breast milk iodine concentration, and mammary gland iodine content in the 50HI group were significantly higher than those in the NI group (p < 0.05). Compared with the NI group, NIS expression in the 50HI group significantly decreased (p < 0.05). DAPGT1 expression was significantly higher in the LI group than in the NI group (p < 0.05). The expression level of VCP was significantly increased in the 10HI and 50HI groups. In conclusion, milk iodine concentration is positively correlated with iodine intake, and the lactating mammary gland regulates the glycosylation and degradation of NIS by regulating DPAGT1 and VCP, thus regulating milk iodine level. However, the mammary gland has a limited role in compensating for iodine deficiency and excess.

In this work, we incorporate matrix projections into the reduced rank regression method, and then develop reduced rank regression estimators based on random projection and orthogonal projection in high-dimensional multivariate linear regression model. We propose a consistent estimator of the rank of the coefficient matrix and achieve prediction performance bounds for the proposed estimators based on mean squared errors. Finally, some simulation studies and a real data analysis are carried out to demonstrate that the proposed methods possess good stability, prediction performance and rank consistency compared to some other existing methods.

With widening deployments of natural language processing (NLP) in daily life, inherited social biases from NLP models have become more severe and problematic. Previous studies have shown that word embeddings trained on human-generated corpora have strong gender biases that can produce discriminative results in downstream tasks. Previous debiasing methods focus mainly on modeling bias and only implicitly consider semantic information while completely overlooking the complex underlying causal structure among bias and semantic components. To address these issues, we propose a novel methodology that leverages a causal inference framework to effectively remove gender bias. The proposed method allows us to construct and analyze the complex causal mechanisms facilitating gender information flow while retaining oracle semantic information within word embeddings. Our comprehensive experiments show that the proposed method achieves state-of-the-art results in gender-debiasing tasks. In addition, our methods yield better performance in word similarity evaluation and various extrinsic downstream NLP tasks., Comment: Accepted by AAAI 2022

Context The effectiveness of saliva iodine concentration (SIC) in evaluating iodine status in children is not clear. Objective We aimed to explore associations between SIC and assessed indicators of iodine status and thyroid function. Design Cross-sectional study. Setting Primary schools in Shandong, China. Participants Local children aged 8 to 13 years with no known thyroid disease were recruited to this study. Main outcome measures Blood, saliva, and urine samples were collected to evaluate thyroid function and iodine status. Results SIC positively correlated with spot urinary iodine concentration (r = 0.29, P < 0.0001), 24-hour urinary iodine concentration (r = 0.35, P < 0.0001), and 24-hour urinary iodine excretion (r = 0.40, P < 0.0001). The prevalence of thyroid nodules (TN) and goiter showed an upward trend with SIC quantiles (P for trend < 0.05). Children with SIC 273 μg/L were associated with greater risks of TN (OR = 2.70; 95% CI, 1.38-5.26) and excessive iodine status (OR = 18.56; 95% CI, 5.66-60.91) than those with lower SIC values. Conclusions There is a good correlation between SIC and urinary iodine concentrations. It is of significant reference value for the diagnosis of iodine deficiency with SIC of less than 105 μg/L and for the diagnosis of iodine excess and TN with SIC of more than 273 μg/L. Given the sanitary nature and convenience of saliva iodine collection, SIC is highly recommended as a good biomarker of recent iodine status in school-aged children.

Structure-based optimization was conducted to improve the potency, selectivity, and cell-based activities of β-catenin/B-cell lymphoma 9 (BCL9) inhibitors based on the 4′-fluoro-N-phenyl-[1,1′-biphenyl]-3-carboxamide scaffold, which was designed to mimic the side chains of the hydrophobic α-helical hot spots at positions i, i + 3, and i + 7. Compound 29 was found to disrupt the β-catenin/BCL9 protein–protein interaction (PPI) with a K(i) of 0.47 μM and >1900-fold selectivity for β-catenin/BCL9 over β-catenin/E-cadherin PPIs. The proposed binding mode of new inhibitors was consistent with the results of site-directed mutagenesis and structure–activity relationship studies. Cell-based studies indicated that 29 disrupted the β-catenin/BCL9 interaction without affecting the β-catenin/E-cadherin interaction, selectively suppressed transactivation of Wnt/β-catenin signaling, downregulated expression of Wnt target genes, and inhibited viability of Wnt/β-catenin-dependent cancer cells in dose-dependent manners. A comparison of the biochemical and cell-based assay results offered the directions for future inhibitor optimization.

To investigate the consumption status of iodized and iodine-free salt and the attitude and reasons for Tianjin residents to choose salt after the reformation of the salt industry systems, and to provide a scientific basis for iodine supplementation and protect the public iodine adequate.Stratified sampling method was used to investigate supermarkets of different sizes in 16 districts of Tianjin from December 2017 to May 2018. And 4-8 different sizes supermarkets were selected in the east, south, west, north, and middle directions of each district, and 25 consumers were selected in each district to conduct a questionnaire survey by Population Proportionate Sampling(PPS). Questionnaire survey was used by investigators to ask and record the respondents age, gender, salt type, time to eat a bag of salt, number of people dining, frequency of seafood consumption, special populations in the family(children, pregnant women or lactating women), reasons for choosing iodized salt or iodine-free salt. And the supermarket sales staff were questioned on the type and proportion of salt sold, the monthly sales of iodized salt and non-iodized salt, and the trend of sales volume.The sales volume of iodized salt was significantly greater than that of noniodized salt in the 94 different supermarkets(P0. 05). Supermarkets with a rise in sales volume of non-iodized salt and iodized salt accounted for 40. 0% and 32. 9%, respectively. Significance difference was found in the prevalence of thyroid disease among people with different salt selection types(χ~2= 15. 052, P0. 05). The prevalence of thyroid disease is higher in the non-iodized salt group. No significant difference was found in the prevalence of thyroid disease between different genders and age groups(χ~2= 0. 937, P0. 05; χ~2=2. 442, P0. 05). From the reasons why consumers choose different types of salt, the choice of iodized salt in the population, habits(45. 0%) accounted for a larger proportion, the prevention of thyroid disease accounted for 49. 6%. Among the people who chose to have no iodized salt, it is considered that Tianjin is a seaside city that does not need iodine supplementation, accounting for 55. 9%, and those who prevent thyroid disease account for 35. 6%. Prevention of thyroid disease account for 46. 9% and those who do not need iodine supplementation account for 40. 0% in a mixed population.There are blindness and misunderstanding when consumers select the type of salt.

Objectives: To explore trimester-specific thyroid function changes under different iodine statuses throughout pregnancy. Methods: A cross-sectional study was conducted to assess the pregnancy iodine status, and 2,378 healthy pregnant women covering all 3 trimesters were recruited. Urinary iodine concentration (UIC) was measured by collecting spot urine samples. Blood samples were collected to evaluate thyroid function. Thyroid B-ultrasonography was conducted to measure the thyroid volume (Tvol). Results: The median UIC was 168 μg/L (111–263 μg/L). The UIC, free triiodothyronine (FT3), and free thyroxine (FT4) were significantly decreased as the pregnancy progressed (p < 0.001, p for trend p < 0.001, p for trend p < 0.001), but the p for trend was not significant (p for trend = 0.88). After stratification by UIC, there were no significant differences in serum TSH, FT4, or FT3 level between UIC groups. Tvol was significantly higher in the UIC ≥500 μg/L group in the first trimester (β: 2.41, 95% CI: 1.09–3.72, p p < 0.001) and UIC ≥500 μg/L group (β: 3.35, 95% CI: 1.96–4.74, p < 0.001) in the third trimester. Conclusions: No difference was observed in TSH, FT3, or FT4 among the different iodine status groups throughout pregnancy. Tvol increased as the pregnancy progressed, and it was especially higher in the UIC ≥500 μg/L group in the first and third trimesters.

The aim of this study was to observe the variation of iodine concentration in breast milk and urine in exclusively breastfeeding women and their infants during the first 24 wk after childbirth.In all, 634 exclusively breastfeeding mother-infant pairs were enrolled at hospital and followed at the 1, 4, 8, 12, 16, and 24 wk postpartum. Spot infant urinary iodine concentration (I-UIC), maternal urinary iodine concentration UIC (M-UIC), and breast milk iodine concentration (BMIC) in bilateral breasts were measured.During the first 24 wk, the median I-UIC was 216 (139-362) and 122 (68-217) μg/L in lactating mothers, both indicating iodine sufficiency. A strong correlation and no difference were found between BMIC in bilateral breasts. The mean BMIC (M-BMIC) of the two breasts was 165 (112-257) μg/L with a Bland-Altman index of 2.1%. Positive correlations were found between M-BMIC and I-UIC (r = 0.353, P0.001), between M-BMIC and M-UIC (r = 0.339, P0.001), and between I-UIC and M-UIC (r = 0.222, P0.001). M-BMIC was significantly higher than M-UIC (P0.001) and lower than I-UIC (P0.001). M-BMIC declined from week 1 to week 8 postpartum, both I-UIC and M-UIC dropped from week 1 to week 4 postpartum and stabilized thereafter.The iodine nutrition in lactating women and infants were adequate during the first 24 wk after childbirth. M-BMIC declined from week 1 to week 8 postpartum. Both I-UIC and M-UIC dropped from week 1 to week 4 postpartum. Further studies are needed to explore a more definitive BMIC and UIC range for an optimal iodine status in lactating women and breastfed infants.

This study aims to evaluate the association of serum iodine concentration (SIC) with urinary iodine concentration (UIC) and thyroid function in pregnant women, as well as to provide the reference range of SIC of pregnant women in iodine-sufficiency area.Pregnant women were enrolled in the Department of Obstetrics, Tanggu Maternity Hospital, Tianjin from March 2016 to May 2017. Fasting venous blood and spot urine samples were collected. Serum free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), thyroglobulin (Tg), thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), UIC and SIC were measured.One thousand and ninety-nine participants were included in this study. The median UIC was 156 μg/L. The median SIC was 108 μg/L, and the 95% reference interval for SIC was 65.6-164.7 μg/L. SIC was positively correlated with UIC (r = 0.12, P 0.001), FT3 (r = 0.23, P 0.001), and FT4 (r = 0.50, P 0.001) and was inversely correlated with TSH (r = -0.14, P 0.001). Pregnant women with a SIC 79.9 μg/L had a higher risk of hypothyroxinemia compared to those with higher SIC (OR = 2.44, 95% CI: 1.31-4.75). Those having SIC 138.5 μg/L were more likely to have thyrotoxicosis than those with lower SIC values (OR = 13.52, 95% CI: 4.21-43.36).Serum iodine level is associated with UIC and thyroid function in pregnant women. Low SIC was associated with increased risk for iodine deficiency and hypothyroxinemia, while high SIC was related to excess and thyrotoxicosis.

In regression analysis, the principal components regression estimator (PCRE) is often used to alleviate the effect of multicollinearity by deleting the principal components variables with smaller eigenvalues, but it has some drawbacks for subset selection. So another effective estimator based on the principal components, termed the principal correlation components estimator (PCCE), has been proposed, which selects the variables by considering the correlation coefficients between the principal components variables and the response variable. In this paper we investigate the property of the PCCE and its optimality. We prove that the PCCE is an admissible estimator and obtain the condition that the PCCE performs better than the PCRE under the balanced loss function (BLF). As an improvement of the least squares estimator (LSE), the conditions that the PCCE performs better than LSE under the BLF and the Pitman closeness criterion are derived in the paper. The empirical performance of the PCCE is demonstrated by several real and simulation data examples.

Protein–protein interactions (PPIs) are important targets for the development of chemical probes and therapeutic agents. From the initial discovery of the existence of hot spots at PPI interfaces, it has been proposed that hot spots might provide the key for developing small-molecule PPI inhibitors. However, there has been no review on the ways in which the knowledge of hot spots can be used to achieve inhibitor design, nor critical examination of successful examples. This Digest discusses the characteristics of hot spots and the identification of druggable hot spot pockets. An analysis of four examples of hot spot-based design reveals the importance of this strategy in discovering potent and selective PPI inhibitors. A general procedure for hot spot-based design of PPI inhibitors is outlined.

It is found that the path adjustment factor or the rainfall adjustment factor achieved from most of model is greater than 1 in short path by analyzing the prediction model of rain attenuation currently available in terrestrial links. It is inconsistent with the assumption that the shorter the propagation path length is, the more uniformly distributed spatially and temporally the rainfall rate is. The measured path adjustment factor for short path is analyzed based on the ITU-R SG3 database and data measured by Chinese researchers. It can be inferred that the phenomena that the path adjustment factor or the rainfall adjustment factor obtained from the model is greater than 1 in the short distance is caused by the insufficient of ITU-R SG3 database in short path. Therefore more experimental data should be collected to make the model agree better with the experimental data in short path.

As an important parameter in the process of ionospheric tomography, TEC (Total Electron Content) plays an important role in the high accuracy inversion of the ionospheric electron density. In this paper, two methods are introduced to calculate the absolute TEC including two-station method and multi-station method. Then we make a thorough performance evaluation for these two methods. After the computation of absolute TEC, the MART method is used to analyze the ionospheric electron density in the mid and low latitude regions. So we can find the variation of electron density with latitude and the differences between day and night from the measure data.