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Targeted radionuclide therapy, in which radiopharmaceuticals deliver potent radionuclides to tumours for localized irradiation, has addressed unmet clinical needs and improved outcomes for patients with cancer1–4. A therapeutic radiopharmaceutical must achieve both sustainable tumour targeting and fast clearance from healthy tissue, which remains a major challenge5,6. A targeted ligation strategy that selectively fixes the radiopharmaceutical to the target protein in the tumour would be an ideal solution. Here we installed a sulfur (VI) fluoride exchange (SuFEx) chemistry-based linker on radiopharmaceuticals to prevent excessively fast tumour clearance. When the engineered radiopharmaceutical binds to the tumour-specific protein, the system undergoes a binding-to-ligation transition and readily conjugates to the tyrosine residues through the ‘click’ SuFEx reaction. The application of this strategy to a fibroblast activation protein (FAP) inhibitor (FAPI) triggered more than 80% covalent binding to the protein and almost no dissociation for six days. In mice, SuFEx-engineered FAPI showed 257% greater tumour uptake than did the original FAPI, and increased tumour retention by 13-fold. The uptake in healthy tissues was rapidly cleared. In a pilot imaging study, this strategy identified more tumour lesions in patients with cancer than did other methods. SuFEx-engineered FAPI also successfully achieved targeted β- and α-radionuclide therapy, causing nearly complete tumour regression in mice. Another SuFEx-engineered radioligand that targets prostate-specific membrane antigen (PSMA) also showed enhanced therapeutic efficacy. Considering the broad scope of proteins that can potentially be ligated to SuFEx warheads, it might be possible to adapt this strategy to other cancer targets.Radiopharmaceuticals engineered with click chemistry to selectively bind to tumour-specific proteins can be used to successfully target tumour cells, boosting the pharmacokinetics of radionuclide therapy and improving tumour regression. [ABSTRACT FROM AUTHOR]

Background: Headache is one of the most common neurological symptoms. Headache disorders are associated with a high global burden of disease. Prior studies indicate that short-to-medium term sodium reduction reduces headache symptom. This study evaluated the effects of long-term reduced-sodium, added-potassium salt on headache frequency and severity in rural China. Methods: The Salt substitute and stroke study (SSaSS) was an open-label cluster-randomised trial in rural China designed to evaluate the effect of salt substitution on mortality and cardiovascular events. Participants included adults with a history of prior stroke and those aged ≥60 years with uncontrolled high blood pressure (BP). Villages were randomly assigned in a 1:1 ratio either to intervention with salt substitute (75% sodium chloride and 25% potassium chloride by mass) or to control with continued use of regular salt (100% sodium chloride). In this pre-specified analysis, between-group differences in headache frequency and severity were evaluated. The study was registered with ClinicalTrials.gov (identifier number: NCT02092090). Results: A total of 20,995 participants were included in the trial (mean age 64.3 years, 51% female, mean follow-up 4.7 years). At final follow-up at the end of the study, headache outcome data including frequency and severity of headaches was available for 16,486 (98%) of 16,823 living participants. Overall, 4454/16,486 (27%) individuals reported having headache: 27.4% in the intervention group (2301/8386) vs 26.6% in the control group (2153/8100) (RR 1.04, 95% CI: 0.93, 1.16, p = 0.48). There was no difference in headache severity between intervention and control groups (p = 0.90). Conclusion: Long term salt substitution did not reduce the frequency or severity of headaches in this population. [ABSTRACT FROM AUTHOR]

The irregular satellites within the Jupiter system hold high scientific value due to their potential to contain clues about the early evolution of the solar system. This paper proposes an optimization algorithm for multiple irregular satellites flyby trajectories, which includes the powered gravity assist from Galilean moons. The algorithm is based on beam search and uses virtual trajectories to determine potential flyby targets, solving for trajectories that satisfy constraints on velocity increment, mission duration, and perijove radius. By changing the initial orbital period and optimizing the number of branches with Galilean moon gravity assist during branching, and comparing with the case without Galilean moon gravity assist, the effects of these factors on the number of irregular satellite flybys are summarized. The simulation results show that the algorithm can effectively solve for orbits that flyby multiple irregular satellites for initial orbits of different periods. The three trajectories obtained can serve as references for future missions. [ABSTRACT FROM AUTHOR]

It is crucial to investigate the characteristics of fire danger in the Beijing-Tianjin-Hebei (BTH) region to improve the accuracy of local fire danger monitoring, forecasting, and management. With the use of instrumental observation data from 173 national meteorological stations in the BTH region from 1991 to 2020, the fire weather index (FWI) is first calculated in this study, and its spatiotemporal characteristics are analyzed. The high- and low-fire danger periods based on the FWI occur in April and August, respectively, with significant decreasing and increasing trends throughout the BTH region over the past 30 years. Next, the contributions of different meteorological factors to the FWI are quantified via a detrending technique. Most regions are affected by precipitation during the high-fire danger period. Both the maximum surface air temperature (Tmax) and precipitation, however, notably contribute to the FWI trend changes during the low-fire danger period. Then, we assess the linkage with atmospheric circulation. Abundant water vapor from the Northwest Pacific and local upward motion jointly lead to increased precipitation and, as a consequence, a decreased FWI during the high-fire danger period. A lack of water vapor from the boreal zone and local downward movement could cause adiabatic subsidence and hence, amplify the temperature and FWI during the low-fire danger period. In contrast to shared socioeconomic pathway (SSP) 585, in which the FWI in the BTH region exhibits a north–south dipole during the low-fire danger period, SSP245 yields an east–west dipole during the low-fire danger period. This study reveals that there is a higher-than-expected probability of fire danger during the low-fire danger period. Therefore, it is essential to intensify research on the fire danger during the low-fire danger period to improve our ability to predict summer fire danger. [ABSTRACT FROM AUTHOR]

Purpose: Anatomical and molecular staging strategies are needed for the personalized treatment of localized pancreatic ductal adenocarcinoma (PDAC). This study evaluated the performance of [68 Ga]Ga–FAPI-04 and [18F]F-FDG PET/CT on the disease staging and prognostic value of patients with localized PDAC on contrast-enhanced (CE)-CT images. Methods: Patients with suspected localized PDAC on CE-CT were recruited for static [68 Ga]Ga-FAPI-04 and 18[F]F-FDG and PET/CT, and select patients underwent simultaneous 60-min dynamic 68 Ga-FAPI-04 PET/CT. The diagnostic and staging performances of the static PET/CT results were evaluated by delineating regions of interest in the primary tumor, whole pancreas, and distal pancreas in both types of scans and then evaluating correlations between the PET/CT findings and clinicopathological characteristics. Furthermore, Kaplan–Meier and hazard ratio (log-rank) methods were used to evaluate the prognostic value of the combined dynamic [68 Ga]Ga-FAPI-04 and static [18F]F-FDG PET/CT method. Results: We included 49 patients with histologically confirmed PDAC adenocarcinomas; 32 underwent 60-min dynamic [68 Ga]Ga-FAPI-04 PET/CT imaging simultaneously. The static [68 Ga]Ga-FAPI-04 method had significantly higher accuracy and uptake values than the static [18F]F-FDG method for primary PDAC lesions, metastatic lymph nodes, and distal metastases. Furthermore, 18.4% and 10.2% of the patients' stages changed after using the [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT methodologies, respectively, compared to the CE-CT-designated stage. The Ki values obtained from dynamic [68 Ga]Ga-FAPI-04 PET/CT did not differ between PDAC and distal obstructive pancreatitis lesions. Pathologically enlarged tumor size, poor differentiation, and perineural invasion were associated with increased [68 Ga]Ga-FAPI-04 uptake but not with [18F]F-FDG uptake. The preoperative prognostic performance of [68 Ga]Ga-FAPI-04 was better than that of [18F]F-FDG. Interestingly, combined [68 Ga]Ga-FAPI-04 and [18F]F-FDG uptake results in the whole pancreas could further stratify patients based on their postoperative prognosis. Conclusion: 6[68 Ga]Ga-FAPI-04 PET/CT was more sensitive and accurate than [18F]F-FDG PET/CT for tumor, node, and metastasis staging of PDAC identified on CE-CT. Additionally, [68 Ga]Ga-FAPI-04 uptake was significantly associated with pathologically aggressive tumor features. Combined [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT findings improved the prognostic value, potentially providing a non-invasive guide for clinical management. Finally, increased fibroblast activity in PDAC-induced obstructive pancreatitis may be associated with poor patient survival rates. [ABSTRACT FROM AUTHOR]

Purpose: Our aim was to assess the prognostic value of [68 Ga]Ga-FAPI-04 positron emission tomography (PET) uptake in PDAC and to evaluate the correlation between in vivo lesional radioactivity with pathological characteristics of pancreatic ductal adenocarcinoma (PDAC). Methods: We retrospectively analyzed treatment‐naïve PDAC patients who underwent preoperative [68 Ga]Ga-FAPI-04 PET/CT followed by pancreatectomy. The tracer uptake was determined as maximum tumor standardized uptake value (SUVmax), FAPI-avid tumor volume (FTV), total lesion FAP expression (TLF) as well total pancreatic uptake (TSUVmax), total FAPI-avid pancreatic volume (FPV), and total pancreatic FAP expression (TPF). Spearman's correlation analysis was performed to evaluate the association between [68 Ga]Ga-FAPI-04 PET/CT imaging and ex vivo immunohistological FAP expression and pathological characteristics of surgical specimens (differentiation, size, vascularity, perineural invasion, and lymph node metastases). Kaplan–Meier and hazard ratio (HR, log-rank) methods were used to evaluate the prognostic value of [68 Ga]Ga-FAPI-04 PET/CT and clinicopathological factors. Results: Thirty-seven surgical PDAC patients were included. The ex vivo expression of FAP was significantly associated with the tumor SUVmax and TLF. FAP expression was more abundant in poorly differentiated PDAC than in well- to moderately differentiated neoplasms. Tumor SUVmax or TLF and pancreatic TSUVmax or TPF were significantly correlated with tumor size, differentiation, and perineural invasion, respectively. SUVmax had a significant independent prognostic value for recurrence-free survival (HR = 2.46, P < 0.05), while [68 Ga]Ga-FAPI-04 TPF predicted overall survival (HR = 12.82, P < 0.05). Conclusion: The in vivo [68 Ga]Ga-FAPI-04 uptake in localized PDAC showed a significant correlation with ex vivo FAP expression and aggressive pathological characteristics. [68 Ga]Ga-FAPI-04 PET/CT also presented a potential for postoperative prognostication of PDAC. Elevated fibroblast activity induced by obstructive pancreatitis might be associated with the patient's survival. [ABSTRACT FROM AUTHOR]

Hydroclimate reconstruction for the last millennium is essential to understand the differences in hydroclimate extremes and their causes under cold/warm conditions. In this study, the first gridded drought/flood grades (D/F grades) dataset in eastern China (EC) during the last millennium was generated. This D/F grades dataset mainly consisted of two components. The first section was created by interpolating drought/flood grades from 1500 to 2000 using the angular distance weight method. Sampling error estimates were employed to assess the effects of the interpolated dataset. The second section for the D/F grades dataset during 960–1500 was generated by constructing best subset regression models using selected tree-ring chronologies in the United States through atmospheric teleconnection. The validation parameters of the calibration equations were also derived, including the adjusted R2, predicted R2, RE, and CE. This dataset provides critical support for investigating the characteristics and causes of hydroclimate extremes in EC at various spatiotemporal scales, as well as the relationship with climate modes, such as El Niño-Southern Oscillation, Pacific Decadal Oscillation, and East Asia Summer Monsoon. [ABSTRACT FROM AUTHOR]

Purpose: To determine the optimal imaging tool for clinical evaluation of pancreatic neoplasm by comparing the performance of 18F-FDG PET/MRI and PET/CT.Procedures: Patients with suspected pancreatic neoplasms underwent PET/MRI and PET/CT in the same day prior to resection or endoscopic ultrasound-guided fine-needle aspiration. Histology served as the golden standard of lesion classification. Visual assessment on lesion type and lesion malignancy via PET/MRI and PET/CT images was compared. Standard uptake values (SUVs) of PET images from the two scanners were measured and their correlations were further evaluated.Results: Thirty-nine patients were included for the final analysis. In visual assessment, we found MRI achieved better performance than CT in differentiating solid and cystic neoplasms, with accuracy of 100% vs. 87%, respectively. In visual malignancy diagnosis, the accuracy of PET/CT was 92.3% for overall lesions and 90.9% for cysts, while the accuracy of PET/MRI was 92.3% and 86.4%, respectively. Besides, semi-quantitative analysis achieved better specificity than visual assessment for both hybrid modalities (100% vs. 87.5% for PET/CT; 100% vs. 81.5% for PET/MR). Furthermore, strong correlation of SUV was found between PET/CT and PET/MRI, with Pearson's correlation coefficients > 0.82.Conclusions: In this study, we found PET/MRI and PET/CT, both using 18F-FDG as tracer, had comparable overall performance in identification of pancreatic neoplasms. Interestingly, for patients who had suspected pancreatic neoplasm but invisible FDG uptake, PET/MRI had shown exceptionally better performance, probably because MR images could detect tiny abnormal structures to improve diagnosis. [ABSTRACT FROM AUTHOR]

This is an extended editors’ commentary on the topical collection “Historical and recent change in extreme climate over East Asia”, which collects a total of 15 papers related to the change and variability of extreme climate events in East Asia over the last few hundreds years. The extreme climate events are broadly classified into three categories: temperature and extreme warmth/coldness, precipitation and floods/droughts and western North Pacific typhoons. This commentary briefly summarizes the main findings presented in each paper in this topical collection, and outlines the implications of these findings for monitoring, detecting and modeling of regional climate change and for studying climate change impacts and adaptability. It also assesses the uncertainties of these studies, as well as the remaining knowledge gaps that should be filled in the future. One solid conclusion we can draw from these studies is that there was a marked decadal to multi-decadal variability of extreme climate events in East Asia in recent history, and the extreme events as observed during the last decades of the instrumental era were still within the range of natural variability except for some of those related to temperature. More severe and enduring droughts occurred in the early 20 th century or the earlier periods of history, frequently leading to great famines in northern China. Uncertainties remain in reconstructing historical extreme climate events and analyzing the early instrumental records. Further research could focus on the improvement of methodology in proxy based reconstruction of multi-decadal variations of surface air temperature and precipitation/drought, the recovery, digitization, calibration and verification of the early instrumental records, and the mechanisms of the observed multi-decadal variability of extreme climate in the region. [ABSTRACT FROM AUTHOR]

An extreme drought occurred from 1876 to 1878 in most regions of northern China, leading to a series of social impacts, including harvest failures, price inflation, and population migration. Most regions of the Northern Hemisphere concurrently experienced extreme drought. Here, we use reconstructed high-resolution hydroclimatic (Palmer Drought Severity Index/precipitation) datasets and investigate the seasonal–annual hydroclimatic spatial patterns and drought intensity in North China from 1876 to 1878. Furthermore, we select combined sea surface temperature (SST) modes with positive Indian Ocean Dipole (IOD)/Pacific Decadal Oscillation (PDO) and El Niño conditions from the 1200-year control run simulations of HadCM3 to determine the possible causes of this severe drought. The extent and intensity of the selected SST modes are similar to those in the Pacific and Indian oceans during the 1876–1878 period from the National Oceanic and Atmospheric Administration (NOAA) Extended Reconstructed Sea Surface Temperature (ERSST) dataset. The results show that the large-scale drought of 1876–1878 is mainly driven by El Niño and a positive PDO, while the effect of IOD is not significant. El Niño may trigger the circumglobal teleconnection of the Northern Hemisphere. And, the meridional disturbance of the eastward Rossby wave train at mid-latitudes may change the intensity of the troughs and ridges and further block water vapor transport from ocean to land. [ABSTRACT FROM AUTHOR]

Purpose: To develop and validate a machine learning model based on radiomic features derived from 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) images to preoperatively predict the pathological grade in patients with pancreatic ductal adenocarcinoma (PDAC). Methods: A total of 149 patients (83 men, 66 women, mean age 61 years old) with pathologically proven PDAC and a preoperative 18F-FDG PET/CT scan between May 2009 and January 2016 were included in this retrospective study. The cohort of patients was divided into two separate groups for the training (99 patients) and validation (50 patients) in chronological order. Radiomics features were extracted from PET/CT images using Pyradiomics implemented in Python, and the XGBoost algorithm was used to build a prediction model. Conventional PET parameters, including standardized uptake value, metabolic tumor volume, and total lesion glycolysis, were also measured. The quality of the proposed model was appraised by means of receiver operating characteristics (ROC) and areas under the ROC curve (AUC). Results: The prediction model based on a twelve-feature-combined radiomics signature could stratify PDAC patients into grade 1 and grade 2/3 groups with AUC of 0.994 in the training set and 0.921 in the validation set. Conclusion: The model developed is capable of predicting pathological differentiation grade of PDAC based on preoperative 18F-FDG PET/CT radiomics features. [ABSTRACT FROM AUTHOR]

Background: 99mTc-PYP scintigraphy provides differential diagnosis of ATTR cardiomyopathy (ATTR-CM) from light chain cardiac amyloidosis and other myocardial disorders without biopsy. This study was aimed to assess the diagnostic feasibility and the operator reproducibility of 99mTc-PYP quantitative SPECT. Method: Thirty-seven consecutive patients who underwent a 99mTc-PYP thorax planar scan followed by SPECT and CT scans to diagnose suspected ATTR-CM were enrolled. For the quantitative SPECT, phantom studies were initially performed to determine the image conversion factor (ICF) and partial volume correction (PVC) factor to recover 99mTc-PYP activity concentration in the myocardium for calculating the standardized uptake value (SUV) (unit: g/ml). SUVmax was compared among groups of ATTR-CM, AL cardiac amyloidosis, and other pathogens (others) and among categories of Perugini visual scores (grades 0–3). The intra- and inter-operator reproducibility of quantitative SPECT was verified, and the corresponded repeatability coefficient (RPC) was calculated. Results: The ICF was 79,327 Bq/ml to convert count rate in pixel to 99mTc activity concentration. PVC factor as a function of the measured activity concentration ratio in the myocardium and blood-pool was [y = 1.424 × (1 − exp(− 0.759 × x)) + 0.104]. SUVmax of ATTR-CM (7.50 ± 2.68) was significantly higher than those of AL (1.96 ± 0.35) and others (2.00 ± 0.74) (all p < 0.05). SUVmax of grade 3 (8.95 ± 1.89) and grade 2 (4.71 ± 0.23) were also significantly higher than those of grade 1 (1.92 ± 0.31) and grade 0 (1.59 ± 0.39) (all p < 0.05). Correlation coefficient (R2) of SUVmax reached 0.966 to 0.978 with only small systematic difference (intra = − 0.14; inter = − 0.23) between two repeated measurements. Intra- and inter-operator RPCs were 0.688 and 0.877. Conclusions: 99mTc-PYP quantitative SPECT integrated with adjustable PVC factors is feasible to quantitatively and objectively assess the burden of cardiac amyloidosis for diagnosis of ATTR-CM. [ABSTRACT FROM AUTHOR]

The Medieval Climate Anomaly (MCA, AD950-1250) is the most recent warm period lasting for several hundred years and is regarded as a reference scenario when studying the impact of and adaptation to global and regional warming. In this study, we investigated the characteristics of temperature variations on decadal-centennial scales during the MCA for four regions (Northeast, Northwest, Central-east, and Tibetan Plateau) in China, based on high-resolution temperature reconstructions and related warm-cold records from historical documents. The ensemble empirical mode decomposition method is used to analyze the time series. The results showed that for China as a whole, the longest warm period during the last 2000 years occurred in the 10th–13th centuries, although there were multi-decadal cold intervals in the middle to late 12th century. However, in the beginning and ending decades, warm peaks and phases on the decadal scale of the MCA for different regions were not consistent with each other. On the inter-decadal scale, regional temperature variations were similar from 950 to 1130; moreover, their amplitudes became smaller, and the phases did not agree well from 1130 to 1250. On the multi-decadal to centennial scale, all four regions began to warm in the early 10th century and experienced two cold intervals during the MCA. However, the Northwest and Central-east China were in step with each other while the warm periods in the Northeast China and Tibetan Plateau ended about 40–50 years earlier. On the multi-centennial scale, the mean temperature difference between the MCA and Little Ice Age was significant in Northeast and Central-east China but not in the Northwest China and Tibetan Plateau. Compared to the mean temperature of the 20th century, a comparable warmth in the MCA was found in the Central-east China, but there was a little cooling in Northeast China; meanwhile, there were significantly lower temperatures in Northwest China and Tibetan Plateau. [ABSTRACT FROM AUTHOR]

Using multiple proxy data of historical hydroclimate variations, this study first selects the five heaviest megadrought decades in North China during the last millennium and then depicts the spatial pattern of hydroclimate over the Northern Hemisphere through these five megadrought decades. The results shows that abnormally dry conditions existed in East Asia, North America, and Europe when megadroughts in North China during the last millennium. The intensity of dry conditions in North America was stronger than that in Europe. Then, through comparing the spatial patterns of hydroclimate from proxy data with ensemble modeling of nine CMIP5/PMIP3 models, we find that such megadroughts in North China, and the contemporaneously abnormal dry conditions over the Northern Hemisphere were very likely mainly induced by external forcing, i.e., large volcanic eruptions and weakened solar irradiation. These external forcing may lead to climate cooling and, hence, air motion downward at mid-lower layer of troposphere, inducing a much more stable troposphere; as well as, the land-ocean pressure differences were weakened, and, hence, there would be decreased water vapor flux from ocean to land. Both of intensified stability of troposphere and weakened vapor transportations to land would lead to precipitation decline and, as a result, would be favorable for drought. It is therefore necessary to consider these external forcing into future climate change predicting to improve our ability of predicting megadrought. [ABSTRACT FROM AUTHOR]

We identified regional differences over China of winter temperature response to large volcanic eruptions with different latitudes and seasons from 1956 to 2005, and investigated atmospheric circulations for corresponding spatial patterns of winter temperature anomalies using reanalysis data and simulations by the Community Earth System Model. Both observations and simulations show that spatial patterns of winter temperature anomalies over China are related to the latitudes and seasons of the eruptions. Tropical volcanic eruptions during summer led to winter temperature decreases of 0.4–1.6 °C in eastern China due to the increase of height gradient. Winter volcanic eruptions led to extensive warming over Tibet. Following summer volcanic eruptions at low latitude, there were warm winters in eastern China because of a weak Siberian high. An anomalous southerly wind caused slight warming over most of China following winter eruptions. With the typical "trough–ridge–trough" at high latitude of the Northern Hemisphere, the winter temperature decreased in northeastern China and increased in western China following summer eruptions at mid-latitude. However, temperature generally increased after winter eruptions. For summer eruptions at high latitude, winter temperature showed a coherent decrease over northwest and east-central China due to an intensified Siberian High and East Asian trough. The widespread warming occurred over China because of the meridional circulation between 65°N and 45°N was weaker following winter volcanic eruptions. [ABSTRACT FROM AUTHOR]

Reconstructed hydroclimatic spatial patterns from historical documents, the chronology of El Niño events since 1525, Meiyu (a unique rainy season dominated by the East Asian summer monsoon in eastern China) series since 1736, and a 1000-year control simulation using the Community Earth System Model were used to analyze the occurrence of anomalous summer precipitation patterns over eastern China with El Niño events. The results show that the frequency of the south-flood north-drought during 1525–2005 was significantly higher during El Niño episodes. Specifically, the occurrences of the triple pattern with floods in the Yangtze River Valley but droughts in its north and south (FYRDNS) as well as the dipole pattern with floods in the south but droughts in the north (FSDN) divided by the Yangtze River both increased in El Niño developing years, while the occurrence of FSDN increased in El Niño decaying years. Among 44 severe and extreme Meiyu events over the middle and lower reaches of the Yangtze River in 1736–2016, 75% of events occurred during El Niño episodes. Especially, 80% of extreme Meiyu events occurred in El Niño decaying years. The 1000-year control simulation captured well the reconstructed triple pattern of FYRDNS in developing years and the dipole pattern of FSDN in decaying years, with more noticeable precipitation anomalies for developing years of very strong and extremely strong El Niño events. These results implicated that the El Niño is likely an early signal for the occurrence of the south-flood north-drought over eastern China. [ABSTRACT FROM AUTHOR]

To synthesize zeolites in a safe and cost-saving manner is the first and the most important task for zeolite application in industry. In the present work, FeAPO-5 aluminophosphate molecular sieve with high iron content was ionothermally synthesized by microwave irradiation at ambient pressure using low dosage of eutectic mixture as the solvent. The influences of seed crystals and mechanochemical pretreatment on the synthesis of FeAPO-5 were investigated in detail. The resultant relatively pure FeAPO-5 molecular sieves were characterized by XRD, ICP-AES, SEM, N2 physisorption and UV-Vis diffuse reflectance spectrometer, and their catalytic performances were studied using phenol hydroxylation as a probe reaction. The XRD results revealed that pure FeAPO-5 can be readily obtained from mechanochemically pretreated reactants, regardless of whether or not the seed crystals were added. The ICP-AES measurements suggested that only by using specific seed crystals can pure FeAPO-5 molecular sieve with high iron content be synthesized. The SEM analysis implied that seed crystals may play a role of morphology-directing agent in these syntheses. The catalytic results demonstrated that longer pronounced induction period were only observed over those FeAPO-5 catalysts with sole framework iron species. The different catalytic activity among five selected catalysts was largely determined by their different densities of framework iron species, while the selectivity towards dihydroxybenzene was mainly controlled by the diffusion path length. Under given reaction conditions, FeAPO-5 catalyst with up to 6.79 wt% of iron content gave 42.0% dihydroxybenzene yield with a selectivity of 94.1%. [ABSTRACT FROM AUTHOR]

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Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on observations made during recent decades, reconstructed precipitation for the period A.D. 1736-2000, dry-wet index data for A.D. 500-2000, and a 1000-yr control simulation using the Community Earth System Model with fixed pre-industrial external forcing, the decadal variability of summer precipitation over eastern China is studied. Power spectrum analysis shows that the dominant cycles for the decadal variation of summer precipitation are: 22-24 and quasi-70 yr over the North China Plain; 32-36, 44-48, and quasi-70 yr in the Jiang-Huai area; and 32-36 and 44-48 yr in the Jiang-Nan area. Bandpass decomposition from observation, reconstruction, and simulation reveals that the variability of summer precipitation over the North China Plain, Jiang-Huai area, and Jiang-Nan area, at scales of 20-35, 35-50, and 50-80 yr, is not consistent across the entire millennium. We also find that the warm (cold) phase of the Pacific Decadal Oscillation generally corresponds to dry (wet) conditions over the North China Plain, but wet (dry) conditions in the Jiang-Nan area, from A.D. 1800, when the PDO became strengthened. However, such a correspondence does not exist throughout the entire last millennium. Data-model comparison suggests that these decadal oscillations and their temporal evolution over eastern China, including the decadal shifts in the spatial pattern of the precipitation anomaly observed in the late 1970s, early 1990s, and early 2000s, might result from internal variability of the climate system. [ABSTRACT FROM AUTHOR]

China is distinguished by a prominent monsoonal climate in the east of the country, a continental arid climate in the northwest and a highland cold climate on the Qinghai-Tibet Plateau. Because of the long history of Chinese civilization, there are abundant and well-dated documentary records for climate variation over the whole of the country as well as many natural archives (e.g., tree-rings, ice cores, stalagmites, varved lake sediments and corals) that enable high-resolution paleoclimatic reconstruction. In this paper, we review recent advances in the reconstruction of climate and extreme events over the last 2000 years in China. In the last 10 years, many new reconstructions, based on multi-proxies with wide spatial coverage, have been published in China. These reconstructions enable us to understand the characteristics of climate change across the country as well as the uncertainties of regional reconstructions. Synthesized reconstructed temperature results show that warm intervals over the last 2000 years occurred in AD 1-200, AD 551-760, AD 951-1320, and after AD 1921, and also show that cold intervals were in AD 201-350, AD 441-530, AD 781-950, and AD 1321-1920. Extreme cold winters, seen between 1500 and 1900, were more frequent than those after 1950. The intensity of regional heat waves, in the context of recent global warming, may not in fact exceed natural climate variability seen over the last 2000 years. In the eastern monsoonal region of China, decadal, multi-decadal and centennial oscillations are seen in rainfall variability. While the ensemble mean for drought/flood spatial patterns across all cold periods shows a meridional distribution, there is a tri-pole pattern with respect to droughts south of 25°N, floods between 25° and 30°N, and droughts north of 30°N for all warm periods. Data show that extreme drought events were most frequent in the periods AD 301-400, AD 751-800, AD 1051-1150, AD 1501-1550, and AD 1601-1650, while extreme flood events were frequent in the periods AD 101-150, AD 251-300, AD 951-1000, AD 1701-1750, AD 1801-1850, and AD 1901-1950. Between AD 1551-1600, extreme droughts and flood events occurred frequently. In arid northwest China, climate was characterized by dry conditions in AD 1000-1350, wet conditions in AD 1500-1850, and has tended to be wet over recent decades. On the northeastern Qinghai-Tibet Plateau, centennial-scale oscillations in precipitation have occurred over the last 1000 years, interrupted by several multi-decadal-scale severe drought events. Of these, the most severe were in the 1480s and 1710s. In southwest China, extreme droughts as severe as those seen in Sichuan and Chongqing in 2006 are known to have occurred during historical times. [ABSTRACT FROM AUTHOR]

Using the dataset provided by the Smithsonian Institution's Global Volcanism Program, we have extracted the large volcanic eruptions (volcanic explosivity index ⩾ 4) from the period 1750-2010 and have then analyzed the main characteristics of large volcanic eruptions since 1750 according to their geographic latitudes, their elevations, and the years and months in which they occurred. The results show that most large volcanic eruptions were located around the margins of the Pacific Ocean and the islands of Sumatra and Java, especially in the equatorial regions (10°N-10°S). Large volcanic eruptions were concentrated at 1000-2000 m elevations and in the months of January and April. There were more eruptions in the summer half-year (from April to September) than in the winter half-year (from October to the next March). Large volcanic eruptions have interdecadal fluctuations, including cycles of 15-25 years and 35-50 years, which were detected by Morlet wavelet analysis, with the fluctuations being more frequent after 1870 than before. During the periods 1750-1760, 1776-1795, 1811-1830, 1871-1890, 1911-1920 and 1981-1995, there were relatively many large volcanic eruptions. [ABSTRACT FROM AUTHOR]

Based on the reconstructed temperatures, precipitation changes, and occurrences of extreme climate events, together with historical records on fiscal deterioration, food crises, and the frequencies of popular unrest, rebellions and wars, we identified three principal ways in which climate change contributed to the collapse in the Ming dynasty. Firstly, cooling, aridification, and desertification during a cold period destroyed the military farm system, which was the main supply system for the provisioning of government troops on the northern frontiers; these impacts increased the military expenditure from 64 % of total government expenditure in 1548-1569 to 76 % in 1570-1589 and thus aggravated the national fiscal crisis that occurred during the late Ming dynasty. Secondly, climate deterioration (e.g., cooling, aridification, and an increase in the frequencies of frost- and drought-related disasters, etc.) led to a 20-50 % reduction in the per capita production of raw grain in most areas of China, which resulted in widespread food crises and exacerbated the vulnerability of social structures during the last several decades of the Ming dynasty. Thirdly, the severe droughts occurring in 1627-1643 were a key trigger to the peasantry uprising. These droughts also played a significant role to promote the peasantry uprising, especially reviving the peasantry troops by recruitment of famine victims when they nearly perished in 1633 and 1638, and severely disrupting the food supply for the government troops, resulting in the final defeat of the government troops by the peasantry troops. This study contributes to an understanding of the climate-related mechanisms behind the collapse of the Ming dynasty, and provides a historical case study that enhances our understanding of the nature of interactions between climate change and social vulnerability. [ABSTRACT FROM AUTHOR]

The starting dates of the pre-summer rainy season during historical times (1736-1911) in Fuzhou and Guangzhou of South China, were determined and reconstructed on the basis of historical documents in the Yu-Xue-Fen-Cun archive, together with observed features of precipitation during the pre-summer rainy season. In addition, starting dates of the pre-summer rainy season from 1953 in Fuzhou and from 1952 in Guangzhou were reconstructed for the instrumental period. These data allowed for analyses of inter-annual and inter-decadal changes in the starting dates of the pre-summer rainy season in South China over the past 300 years. Results show that the mean starting date of the pre-summer rainy season in South China was the first pentad of May; in addition, periodicities in the starting dates of 2-3 years, 10 years, and 40 years were detected during the period 1736-1911, and of 2-3 years, 10 years, and 22 years during the instrumental period. From 1736 to 1911, the earliest starting dates at Fuzhou and Guangzhou both occurred at the fourth pentad of April, while the latest starting dates were at the sixth pentad of May in Fuzhou and the first pentad of June in Guangzhou. During the instrumental period, the earliest and latest starting dates were at the fourth pentad of April and the first pentad of June, respectively, in both Fuzhou during 1953-2010 and Guangzhou during 1952-2010. The maximum difference between neighboring decades during 1736-1911 was 2.2 and 1.6 pentads in Fuzhou and Guangzhou, respectively, and during the instrumental period it was 2.5 and 2.4 pentads in Fuzhou and Guangzhou, respectively. [ABSTRACT FROM AUTHOR]

We present a study of summer precipitation changes over the Yangtze River Valley (YRV) and North China (NC) simulated from 20 models of the CMIP3 (phase 3 of the Coupled Model Intercomparison Project). It is found that the LASG-FGOALS-g1.0 ( fgoals) model has the highest ability in simulating both the interannual variability of individual regions and the seesaw pattern of the two regions observed during the past few decades. Analyses of atmospheric circulations indicate that the variability in precipitation is closely associated with the 850 hPa meridional winds over the two regions. Wetness in the YRV and dryness in NC are corresponding to strong meridional wind gradient and weak meridional wind over these two regions, respectively. The ability of a coupled general circulation model (CGCM) to simulate precipitation changes in the YRV and NC depends on how well the model reproduces both observed associations of precipitation with overlying meridional winds and observed meridional wind features in summer. Analysis of future precipitation changes over the two regions projected by the fgoals model under the IPCC scenarios B1 and A1B suggests a significant increase of 7-15% for NC after 2040s due to the strengthened meridional winds, and a slight increase over the YRV due to less significant intensification of the Mei-yu front. [ABSTRACT FROM AUTHOR]

The general characteristics of climate changes over the past 2000 years in China, regional differences and uncertainties were analyzed based on the recently peer-reviewed high time-resolution climatic reconstructions. The results showed that there exists four warm periods of the temperature variation in China since the Qin Dynasty, including the western and eastern Han Dynasties (200 BC-AD 180), the Sui and Tang dynasties (541-810), the Song and Yuan dynasties (931-1320), and the 20th century, and three cold phases involving the Wei, Jin, and North-South Dynasties (181-540), the late Tang Dynasty (811-930), and the Ming and Qing dynasties (1321-1920). The Song and Yuan warm period is consistent with the Medieval Warm Period over the Northern Hemisphere, and the cold phases of the North-South Dynasties and the Ming and Qing dynasties are paralleled to the Dark Ages Cold Period and the Little Ice Age, respectively. The 13th-15th century could be a shift to the wet condition of the climate, and the low precipitation variability is exhibited in western China prior to 1500. In the context of the climate warming, the pattern of the drought in north and flood in south is prevalent over the eastern China. In addition, the published reconstructions have a high level of confidence for the past 500 years, but large uncertainties exist prior to the 16th century. [ABSTRACT FROM AUTHOR]

Based on phenological records extracted from Chinese historical dairies, spring phenological series in the Yangtze River Delta (YRD) of China since 1834 is reconstructed. Together with temperature and phenological observation data, the indicating significance of spring phenological series to temperature changes is also analyzed. The results are shown as follows. (1) From 1834 to 1893, spring phenodate in the YRD was fluctuated and gradually delayed, but, advanced greatly at the end of the 19th century. From 1900 to 1990, although the decadal variations were found, no clear multi-decadal trend was detected. From 1990 to 2010, spring phenodate showed significantly advance again. Compared with the mean value for 1977-1996, the latest phenodate occurred in 1893 with 27 days delayed while the earliest phenodate occurred in 2007 with 17 days advanced. (2) The correlation coefficients between spring phenodates and temperatures from December to March and from January to March exceeded −0.75 and −0.80, respectively, indicating that our phenodate series well presents the long-term changes of winter and early spring (especially from January to March) temperatures. These results provide important basic data for the long-term integrated temperature reconstruction over China in the future work. [ABSTRACT FROM AUTHOR]

The spatial patterns of precipitation anomalies during five 30-yr warm periods of 691-720, 1231-1260, 1741-1770, 1921-1950, and 1981-2000 were investigated using a dryness/wetness grading dataset covering 48 stations from Chinese historical documents and 22 precipitation proxy series from natural archives. It was found that the North China Plain (approximately 35°-40°N, east of 105°E) was dry in four warm periods within the centennial warm epochs of 600-750, the Medieval Warm Period (about 900-1300) and after 1900. A wet condition prevailed over most of China during 1741-1770, a 30-yr warm peak that occurred during the Little Ice Age (about 1650-1850). The spatial pattern of the precipitation anomaly in 1981-2000 over East China (25°-40°N, east of 105°E) is roughly consistent with that in 1231-1260, but a difference in the precipitation anomaly appeared over the Tibetan Plateau. The spatial patterns of the precipitation anomalies over China varied between all five 30-yr warm periods, which implies that the matching pattern between temperature and precipitation change is multiform, and the precipitation anomaly could be positive or negative when a decadal warm climate occurs in different climate epochs. This result may provide a primary reference for the mechanism detection and climate simulation of the precipitation anomaly of the future warm climate. [ABSTRACT FROM AUTHOR]

Using 24 proxy temperature series, the rates of temperature change in China are analyzed at the 30- to 100-year scales for the past 2000 years and at the 10-year scale for the past 500 years. The results show that, at the 100-year scale, the warming rate for the whole of China in the 20th century was only 0.6±1.6°C/100 a (interval at the 95% confidence level, which is used hereafter), while the peak warming rate for the period from the Little Ice Age (LIA) to the 20th century reached 1.1±1.2°C/100 a, which was the greatest in the past 500 years and probably the past 2000 years. At the 30-year scale, warming in the 20th century was quite notable, but the peak rate was still less than rates for previous periods, such as the rapid warming from the LIA to the 20th century and from the 270s-290s to 300s-320s. At the 10-year scale, the warming in the late 20th century was very evident, but it might not be unusual in the context of warming over the past 500 years. The exact timing, duration and magnitude of the warming peaks varied from region to region at all scales. The peak rates of the 100-year scale warming in the AD 180s-350s in northeastern China as well as those in the 260s-410s and 500s-660s in Tibet were all greater than those from the mid-19th to 20th century. Meanwhile, the rates of the most rapid cooling at scales of 30 to 100 years in the LIA were prominent, but they were also not unprecedented in the last 2000 years. At the 10-year scale, for the whole of China, the most rapid decadal cooling in the 20th century was from the 1940s to 1950s with a rate of −0.3±0.6°C/10 a, which was similar to rates for periods before the 20th century. For all regions, the rates of most rapid cooling in the 20th century were all less than those for previous periods. [ABSTRACT FROM AUTHOR]

Based on the reconstructed precipitation series in North China from historical documents, the 1876--1878 drought was identified as the most severe and extreme one in North China over the past 300 years. Meanwhile, the spatial patterns of seasonal and annual precipitation during 1876--1877 were analyzed and the social and economic impacts related with this drought event were evaluated according to the descriptions in the historical documents. The results indicated that this long-lasting drought started by the spring of 1876 and did not stop until the spring of 1878. Within the three years, the harvest failures brought the rice price increased to 5--10 times than that in the normal year, and the total population in the five provinces over North China decreased by more than 20 million due to a large number of dead people and migrations. In addition, related investigations suggested that the 1876--1878 drought was prevalent worldwide, which has possible link with abnormal high SST in the equatorial central and eastern Pacific, strong El Niño episode and positive AAO anomalies. [ABSTRACT FROM AUTHOR]

Based on reconstructions of precipitation events from the rain and snowfall archives of the Qing Dynasty (1736–1911), the drought/flood index data mainly derived from Chinese local gazettes from 1736–2000, and the observational data gathered since 1951, the spatial patterns of monsoon rainbands are analyzed at different time scales. Findings indicate that monsoon rainfall in northern China and the middle-lower reaches of the Yangtze River have significant inter-annual (e.g., 5–7-yr and 2–4-yr) as well as inter-decadal (e.g., 20–30-yr and quasi-10-yr) fluctuation signals. The spatial patterns in these areas also show significant cycles, such as on a 60–80-yr time scale, a reversal phase predominates the entire period from 1736–2000; on a quasi-30-yr time scale, a consistent phase was prevalent from 1736 to 2000; and on a 20-yr time scale, the summer monsoon rains show different spatial patterns before and after 1870. [ABSTRACT FROM AUTHOR]

Based on the long-term precipitation series with annual time resolution in the middle and lower reaches of the Yellow River and its four sub-regions during 1736–2000 reconstructed from the rainfall and snowfall archives of the Qing Dynasty, the precipitation cycles are analyzed by wavelet analysis and the possible climate forcings, which drive the precipitation changes, are explored. The results show that: the precipitation in the middle and lower reaches of the Yellow River has inter-annual and inter-decadal oscillations like 2–4a, quasi-22a and 70–80a. The 2–4a cycle is linked with El Niño events, and the precipitation is lower than normal year in the occurrence of the El Niño year or the next year; for the quasi-22a and the 70–80a cycles, Wolf Sun Spot Numbers and Pacific Decadal Oscillation (PDO) coincide with the two cycle signals. However, on a 70–80a time scale, the coincidence between solar activity and precipitation is identified before 1830, and strong (weak) solar activity is generally correlated to the dry (wet) periods; after 1830, the solar activity changes to 80–100a quasi-century long oscillation, and the adjusting action to the precipitation is be-coming weaker and weaker; the coincidence between PDO and precipitation is shown in the whole time series. Moreover, in recent 100 years, PDO is becoming a pace-maker of the precipitation on the 70–80a time scale. [ABSTRACT FROM AUTHOR]

"Yu Xue Fen Cun" records during the Qing Dynasty are used to identify the starting and ending dates of Meiyu at the period of 1736-1911. These results, along with the instrumental meteorological records, are used to reconstruct the series of length and precipitation of Meiyu during 1736-2000 over the middle and lower reaches of the Yangtze River. The characteristics of Meiyu are analyzed since 1736. Moreover, the strength of East Asian Summer Monsoon and locations of rainband are discussed, based on the relationship between the length of Meiyu and the Index of East Asian Summer Monsoon. It is found that the starting and ending dates and the length of Meiyu have significant interannual and interdecadal variations. Apart from 7-8 years, 20-30 years and 40 years cycles for the lengths of Meiyu, the centennial oscillation is also presented. The length of Meiyu, monsoon rainband movement over eastern China, and the strength of East Asian Summer Monsoon (EASM) have a very good correlation, which can be expressed in the following: during the periods of 1736-1770, 1821-1870 and 1921-1970, the EASM was stronger, and the monsoon rainband was located in North China and South China easily, corresponding to the decreased length of Meiyu. Whereas during the periods of 1771-1820, 1871-1920 and 1971-2000, the EASM was weaker and monsoon rainband usually stopped at the middle and lower reaches of the Yangtze River, corresponding to the increased length of Meiyu. [ABSTRACT FROM AUTHOR]

We review here proxy records of temperature and precipitation in China during the Holocene, especially the last two millennia. The quality of proxy data, methodology of reconstruction, and uncertainties in reconstruction were emphasized in comparing different temperature and precipitation reconstruction and clarifying temporal and spatial patterns of temperature and precipitation during the Holocene. The Holocene climate was generally warm and wet. The warmest period occurred in 9.6–6.2 cal ka BP, whereas a period of maximum monsoon precipitation started at about 11.0 cal ka BP and lasted until about 8.0–5.0 cal ka BP. There were a series of millennial-scale cold or dry events superimposed on the general trend of climate changes. During past two millennia, a warming trend in the 20th century was clearly detected, but the warming magnitude was smaller than the maximum level of the Medieval Warm Period and the Middle Holocene. Cold conditions occurred over the whole of China during the Little Ice Age (AD 1400–AD 1900), but the warming of the Medieval Warm Period (AD 900–AD 1300) was not distinct in China, especially west China. The spatial pattern of precipitation showed significant regional differences in China, especially east China. The modern warm period has lasted 20 years from 1987 to 2006. Bi-decadal oscillation in precipitation variability was apparent over China during the 20th century. Solar activity and volcanic eruptions both were major forcings governing the climate variability during the last millennium. [ABSTRACT FROM AUTHOR]

The precipitation at 17 stations over the middle and lower reaches of the Yellow River is reconstructed during the period of 1736-1910, using the snow and rainfall records in the Qing Dynasty, together with the instrumental observation data of precipitation and farmland soi moisture content. The soil physics model related to rainfall infiltration and the surface water balance equation are taken as main reconstruction methodology. The field infiltration experiment by artificial rainfall is conducted to check the reliability. And the precipitation series over the middle and lower reaches of the Yellow River and its 4 sub-regions are established, going back to 1736. Analysis of the time series indicates that the abrupt change of precipitation from high to low occurs around 1915 over the middle and lower reaches of the Yellow River. During the three periods of 1791-1805, 1816-1830 and 1886-1895, the precipitation is markedly higher than the mean of the series. While both the periods of 1916-1945 and 1981-2000 are characterized by less precipitation. Three periodicities of 22-25a, 3.9a and 2.7a are shown in the precipitation fluctuation over the middle and lower reaches of the Yellow River. Moreover, the periodical signal of 22-25a becomes weaker and weaker since the abrupt change of 1915 and disappears in the late 1940s, and then the periodical signal of 35-40a appears instead. [ABSTRACT FROM AUTHOR]

Presents an analysis of the change of plant phenophase in spring and the impact of climate warming on the plant phenophase in China for the last 40 years, based on plant phenology data from 26 stations of the Chinese Phenology Observation Network of the Chinese Academy of Sciences and the climate data. Reconstruction of the geographical distribution models of phenophase in every decade; Study of the impact of climate warming on geographical distribution model of phenophase;. Description of the results. which show that (i) the response of phenophase advance or delay to temperature change is nonlinear.