Alibaba Group Holding Limited

Zhejiang University

Zhejiang Chiral Medicine Chemicals Co. Ltd.

Qin Zhang

Lei Hou

Ning Guo

Fei Xing

Yuheng Xie

Feng Lin

Jing Dong

Wei Zheng

Yuguo Zheng

Xu Yang

Peng Huang

Huaxing Jin

Renchao Zheng

Jian Liao

Shousong Zhang

Jiong Feng

Jian Qiao Sun

Youming Huang

Tianchun Liu

Weirong Fan

Jianfeng Weng

Zheming Wu

Junlin Zhang

Sheng Peng

Xiaoling Tang

Xiafeng Lu

The present invention discloses a nitrilase mutant and its construction method and its application in the synthesis of chiral intermediate of pregabalin in the technical field of bioengineering. The present invention, respectively, takes turnip nitrilase BrNIT and arabidopsis nitrilase AtNIT as parent, using peptide fragment displacement method, displaces the sites 226-286 of BrNIT amino acid sequence and sites 225-285 of AtNIT amino acid sequence with sites 225-285 ofL. nitrilase AaNIT, obtain nitrilase mutants BrNITand AtNITof which the amino acid sequence is as shown in SEQ ID NO.1 or SEQ ID NO.3. Compared with wild type nitrilase, the activity of the nitrilase mutant provided by the present invention in catalyzing and hydrolyzing racemic IBSN and the stereoselectivity of the product show substantial improvement, it can satisfy the requirements of industrial application, and has good application prospect in efficient catalysis of racemic IBSN to synthesize 3-cyano-5-methylhexanoic Acid.

Nitrilase mutant, construction method therefor, and application thereof

The disclosure provides a nitrilase from, which belongs to genus, family brassicaceae. The disclosure further provides the encoding gene, vector, recombinant bacterial strain, and the application in the manufacturing of (S)-3-cyano-5-methylhexanoic acid. The wet resting cells containing nitrilase Aa-Nit can kinetically resolve racemic IBSN at 1.2 M with a 42% conversion rate in 15 hr and &#x3e;99% ee value. The disclosure provides a regio- and stereoselective method for the preparation of (S)-3-cyano-5-methylhexanoic acid. This method provides an atom economical, mild, environmental friendly industrial method to manufacture (S)-3-cyano-5-methylhexanoic acid.

Nitrilase from arabis alpina, its encoding gene, vector, recombinant bacterial strain and uses thereof

[object Object]

Implementing website navigation includes deriving a confidence level for at least one leaf node of a website navigation category diagram using historical user operation data; generating one or more navigation hierarchical structure diagrams based on the website navigation category diagram; determining a searching cost associated with each of the one or more navigation hierarchical structure diagrams; determining the navigation hierarchical structure diagram associated with the lowest searching cost; and implementing at least in part a website navigation mode using the navigation hierarchical structure diagram associated with the lowest searching cost.

Selecting a navigation hierarchical structure diagram for website navigation

A method for generating a search result includes: receiving, by an information search system, a search request; obtaining, by searching, a plurality of pieces of matching information that match the search request; obtaining a respective amount of user response associated with each of the plurality of pieces of matching information and further obtaining a total amount of user response associated with a respective categories to which each of the plurality of pieces of matching information belongs; and ranking the plurality of pieces of information to generate a search result based on the total amount of user response associated with the respective category to which each of the plurality of pieces of matching information belongs. By using the above technical scheme, a result of more rational ranking of matching information can be displayed to a user when the user performs a search, thus improving experience of the user.

Method for generating search result and system for information search

A search method is disclosed. In the method, a data rewriting system obtains, from a database, one or more search term candidates that are relevant to a present search term. The data rewriting system retrieves properties of the present search term and the one or more search term candidates, where the properties describe respective matching results of the present search term and the one or more search term candidates. Based on the matching results, the data rewriting system determines whether the present search term needs to be rewritten, and rewrites the present search term based on the matching results to provide a rewritten present search term in response to determining that the present search term needs to be rewritten. A search engine performs a search based on the rewritten present search term.

Search method, apparatus and system based on rewritten search term

Generating ranked search results includes receiving a plurality of matching information items that match a search request, ranking at least some of the plurality of matching information items using a linear ranking model that linearly combines a first plurality of feature values to obtain a first set of ranked results, ranking at least some of the first set of ranked results using a nonlinear ranking model that nonlinearly combines a second plurality of feature values to obtain a second set of ranked results, and provide a search response based on the second set of ranked results.

Generating ranked search results using linear and nonlinear ranking models

Providing guided search includes: receiving a new query; processing the new query to obtain a plurality of models, wherein a model indicates a mapping relationship of a previously stored query and corresponding guidance information; determining a corresponding plurality of similarities of the plurality of models relative to the new query; obtaining guidance information in a database comprising a plurality of mapping relationships of previously stored query and corresponding guidance information, including selecting at least some of the plurality of models based at least in part on the similarities and using the selected models as index to search the database; and sending the obtained guidance information to be displayed to a user.

Guided search based on query model

Ordering search results may include obtaining an exposed log file from a log system, computing a Bayesian posterior probability for relevancy between the log file and a search request, computing an expected value of the relevancy between the log file and the search request based on the Bayesian posterior probability, storing the search request and an identifier of the log file as a key and the expected value of the relevancy between the log file and the search request as a value into a search data structure, in response to receiving a search request submitted by a user, finding expected values of relevancy between the submitted search request and log files that are relevant to the submitted search request from the search data structure, and ordering the found log files in a descending order of the expected values.

Method and apparatus of ordering search results

Ranking search results, comprises retrieving search results that include target strings that relate to a query string; segmenting the query string and each of the target strings; pairing segments in the query string with respective segments in the target strings to form combinations; retrieving weights that correspond to the combinations; and determining a weighted word length based on the weights corresponding to each of the target strings; and ranking the target strings based on their respective weighted word lengths. Alternatively, ranking search results includes determining a minimum weight of each inserted word with respect to segments in the query string; determining a minimum weight of each deleted word with respect to segments in the target strings; determining a total edit distance for each target string; and ranking the target strings based on the total edit distances.

Ranking search results based on word weight

A method and an apparatus for identifying synonym and utilizing such synonym to conduct search is disclosed. The disclosed method includes: obtaining arbitrary two words to be identified; determining whether a shortest edit distance between the two words less than or equal to an edit distance threshold; determining whether the two words to be identified exist in a preset knowledge database, and if an answer is yes then searching a smallest granularity type with highest weight value for each word in the knowledge database; and if the two word have the same smallest granularity type with highest weight value, then determining such two words are synonyms, or non-synonym otherwise. The disclosed techniques greatly improve accuracy of synonym identification and guarantee effect of synonym identification.

Method and apparatus for identifying synonyms and using synonyms to search

A search system includes: a data rewriting system that obtains, from a database, one or more search term candidates that are relevant to a present search query. The data rewriting system retrieves properties of the present search query and the one or more search term candidates, where the properties describe respective matching results of the present search query and the one or more search term candidates. Based at least in part on the matching results, the data rewriting system determines whether or not the present search query needs to be rewritten, and rewrites the present search query based at least in part on the matching results to provide a rewritten present search query if it is determined that the present search query needs to be rewritten. A search engine performs a search based at least in part on the rewritten present search query.

Method, apparatus and system, for rewriting search queries

The present disclosure discloses a method for generating a search result and an information search system. The method for generating a search result includes: receiving, by an information search system, a search request; obtaining, by searching, a plurality of pieces of matching information that match the search request; obtaining a respective amount of user response associated with each of the plurality of pieces of matching information and further obtaining a total amount of user response associated with a respective categories to which each of the plurality of pieces of matching information belongs; and ranking the plurality of pieces of information to generate a search result based on the total amount of user response associated with the respective category to which each of the plurality of pieces of matching information belongs. By using the above technical scheme, a result of more rational ranking of matching information can be displayed to a user when the user performs a search, thus improving experience of the user.

Growing community of inventors

Hangzhou, China

Qin Zhang