Effectiveness of convalescent plasma therapy in severe COVID-19 patients.

Currently, there are no approved specific antiviral agents for novel coronavirus disease 2019 (COVID-19). In this study, 10 severe patients confirmed by real-time viral RNA test were enrolled prospectively. One dose of 200 mL of convalescent plasma (CP) derived from recently recovered donors with the neutralizing antibody titers above 1:640 was transfused to the patients as an addition to maximal supportive care and antiviral agents. The primary endpoint was the safety of CP transfusion. The second endpoints were the improvement of clinical symptoms and laboratory parameters within 3 d after CP transfusion. The median time from onset of illness to CP transfusion was 16.5 d. After CP transfusion, the level of neutralizing antibody increased rapidly up to 1:640 in five cases, while that of the other four cases maintained at a high level (1:640). The clinical symptoms were significantly improved along with increase of oxyhemoglobin saturation within 3 d. Several parameters tended to improve as compared to pretransfusion, including increased lymphocyte counts (0.65 × 109/L vs. 0.76 × 109/L) and decreased C-reactive protein (55.98 mg/L vs. 18.13 mg/L). Radiological examinations showed varying degrees of absorption of lung lesions within 7 d. The viral load was undetectable after transfusion in seven patients who had previous viremia. No severe adverse effects were observed. This study showed CP therapy was well tolerated and could potentially improve the clinical outcomes through neutralizing viremia in severe COVID-19 cases. The optimal dose and time point, as well as the clinical benefit of CP therapy, needs further investigation in larger well-controlled trials.

Research on preparation and in vitro evaluation of the dendrimer-peptide nuclear acid conjugate for amplification pretargeting.

Amplification pretargeting has the potential to increase the tracer's accumulation in the tumor. This study aimed to develop a three-step amplification pretargeting strategy in nuclear medicine with a polymer conjugated with multiple copies of peptide nuclear acid (PNA). In this study, the tracer 18 F-labeled complementary PNA (18 F-cPNA) was prepared by click-chemistry with high radiochemical purity (>99%) and great stability in vitro. The PAMMA dendrimer generation 4 (G4) was conjugated with multiple copies of PNAs. The average number of PNA groups in the G4-PNA conjugate was determined by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and the accessibility to the 18 F-cPNA was identified by size-exclusion high-performance liquid chromatography (SE-HPLC). There were approximately 11.7 of 64 carboxyl groups modified with PNAs, of which more than 99% were accessible to 18 F-cPNA. 18 F-cPNA was added to a mixture of CC49-cPNA and G4-PNA, and the complex exhibited a single peak on high-performance liquid chromatography (HPLC) as evidence of complete hybridization between 18 F-cPNA and CC49-cPNA/G4-PNA. The LS174T tumor cells were incubated with CC49-cPNA followed by G4-PNA as an amplification platform before 18 F-cPNA was added to hybridize with CC49-cPNA/G4-PNA. Compared with conventional pretargeting without G4-PNA, the radioactivity signal was amplified about four times, which demonstrated that the dendrimer-PNA conjugate plays a crucial role in signal amplification.

Wh-Questions are understood before polar-questions: Evidence from English, German, and Chinese.

In this paper we consider the order of emergence of comprehension of wh-questions and polar-questions. We argue that considerations of complexity and input favour the earlier emergence of polar questions; on the other hand, if one assumes that question understanding emerges as a consequence of interactive learning this favours (certain) wh-questions, as well as a small subclass of polar questions. We offer corpus evidence from the Providence corpus that (a certain class of) wh-questions are in fact understood earlier than the polar-questions. We test this observation using elicitation studies on German and Chinese speaking children. Our results confirm the finding from the corpus study and are in line with an interactive learning perspective for the emergence of understanding of questions.

Protracted Development on Native Tone Interpretation: Evidence From Mandarin-Learning Infants' Novel Word Learning.

Studies have shown that infants from cultures with tone languages develop categorical perception of their native lexical tone before their first birthday, but few studies have explored whether, and when, they interpret the phonemic function of lexical tone in word learning. Two habituation-switch experiments were conducted to explore whether Mandarin-learning infants could exploit tonal cues during their word learning, and detect a change when the association of two word-object pairs was switched. In Experiment 1, two words were solely differentiated by their lexical tones (/fai/ vs. /fai/), and Mandarin-learning infants failed to detect the switch of tones at 14 months, but succeeded at 18 months. In Experiment 2, two words were markedly distinct (/fai/ vs. /bǒu/), and infants could detect the change of words as early as 14 months. The results indicate that infants may not refer to the lexical function of tone during their novel word learning until 18 months, even though infants from birth are able to distinguish the Tone 1 vs. Tone 3 contrast. Given that lexical tone is expressed by variations of the pitch contours, which are also related to intonation, infants' increasing knowledge of both tone and intonation may contribute to their misinterpretation of pitch contours in word learning at 14 months and, further, to their development of a sophisticated use of the phonemic function of lexical tone at 18 months of age.

[Analysis of lipid compounds of high-yielded rhizoma pinelliae growing in the west of Hubei province by gas chromatography-mass spectrometry].

OBJECTIVE: To investigate lipid components of high-yielded Pinellia ternata rhizomes growing in the west of Hubei province. METHODS: To determine the lipid chemical components in Pinellia ternata rhizomes with GC-MS method and NIST atlas. RESULTS: Ten components have been found: palmitic acid (I), 9,12-octadecadienoic acid (II), pyrrolidine,1-(1-oxo-7,10-hexadecadienyl) (III), alpha-monpalmitin (IV), 1,3,12-nonadecatriene (V), campesterol (VI), stigmasta-5,22-dien-3-ol (VII), beta-sitosterol (VIII), stigmasta-5,24-dien-3-ol (IX), cycloartenol (X). CONCLUSION: The relative contents of five kinds of phytosterol: campesterol 28.96%, stigmasta-5,22-dien-3-ol 9.24%, beta-sitosterol 50.77%, stigmasta-5,24-dien-3-ol 4.74%, cycloartenol 6.25%. Component II, III, V, VI, IX are the first time reported in Pinellia ternata.

Purification and characterization of an anticoagulant oligopeptide from Whitmania pigra Whitman.

BACKGROUND: Dried Whitmania pigra is used for the treatment of cardiovascular and cerebrovascular diseases in traditional Chinese medicine and hot water and alcohol extracts also have anticogulant activity. However, a lower molecular weight and more stable anticogulant is needed. OBJECTIVE: The objective of the following study is to purify and characterize of an anticoagulant oligopeptide from Hirudo (Whitmania pigra Whitman). MATERIALS AND METHODS: Gel filtration on Sephadex G-50, ion exchange on diethylaminoethyl-cellulose, and semi-prepared high-performance liquid chromatography were used to purify Hirudo. Automated coagulation analyzer was used for evaluating anticoagulant activity. Molecular weight was measured by Matrix-assisted laser desorption ionization time of flight mass spectrometry. Amino acid sequence of the oligopeptide was measured by amino acid sequence analyzer. RESULTS: A new anticoagulant, named whitide, isolated from Hirudo was purified, with a molecular weight 1997.1 Da. Amino acid sequence of the oligopeptide was identified as Gly-Pro-ALa-Gly-Hyp-Val-Gly-Ala-Hyp-Gly-Gly-Hyp-Gly-Val-Arg-Gly-Leu-Hyp-Gly-Asp-Arg-Gly. The results revealed that its amino acid sequence had strong homology to various types of collagen. CONCLUSION: Whitide might be an orally anticoagulant for its hot and trypsin stable.

English- and Mandarin-learning infants' discrimination of actions and objects in dynamic events.

The present studies examined the role of linguistic experience in directing English and Mandarin learners' attention to aspects of a visual scene. Specifically, they asked whether young language learners in these 2 cultures attend to differential aspects of a word-learning situation. Two groups of English and Mandarin learners, 6-8-month-olds (n = 65) and 17-19-month-olds (n = 91), participated in 2 studies, based on a habituation paradigm, designed to test infants' discrimination between actions and objects in dynamic events. In Study 1, these stimuli were presented in silence, whereas in Study 2, a verbal label accompanied videos. Results showed that 6-8-month-olds could discriminate action changes but not object changes, whereas 17-19-month-olds could discriminate both types of changes. However, there were only very subtle cross-linguistic differences in these patterns when the scenes were presented together with a verbal label. These findings show strong evidence for universal developmental trends in attention, with somewhat weaker evidence that the differences in the types of words Mandarin- versus English-learning children produce or are exposed to affect attention to different aspects of a scene in the first 2 years of life.

Children's assignment of grammatical roles in the online processing of Mandarin passive sentences.

Children's difficulty understanding passives in English has been attributed to the syntactic complexity, overall frequency, cue reliability, and/or incremental processing of this construction. To understand the role of these factors, we used the visual-world paradigm to examine comprehension in Mandarin Chinese where passives are infrequent but signaled by a highly valid marker (BEI). Eye-movements during sentences indicated that these markers triggered incremental role assignments in adults and 5-year-olds. Actions after sentences indicated that passives were often misinterpreted as actives when markers appeared after the referential noun ("Seal BEI it eat" → The seal is eaten by it). However, they were more likely to be interpreted correctly when markers appeared before ("It BEI seal eat" → It is eaten by the seal). The actions and the eye-movements suggest that for both adults and children, interpretations of passive are easier when they do not require revision of an earlier role assignment.