Task: Schema-Matching (source dataset: assays)

Task: 
Please identify the matching columns between Table A and Table B. For each column in Table A, specify the corresponding column in Table B. If a column in A has no corresponding column in Table B, you can map it to null. Represent each column mapping using a pair of column headers in a list, i.e., [Table A Column, Table B column or null]. Provide the mapping for each column in Table A and return all mappings in a list.

No explanation and return the matching columns in a structured JSON format: {"column_mappings": <a list of column pairs>}.

TableA:
|   assay_id | chembl_id    |   confidence_score |   doc_id | curated_by   | assay_category   | description                                                                                                 | assay_type   | assay_test_type   | assay_organism   | assay_tax_id   | assay_strain   | assay_tissue   | assay_cell_type   |
|-----------:|:-------------|-------------------:|---------:|:-------------|:-----------------|:------------------------------------------------------------------------------------------------------------|:-------------|:------------------|:-----------------|:---------------|:---------------|:---------------|:------------------|
|          1 | CHEMBL615117 |                  8 |    11087 | Autocuration |                  | The compound was tested for the in vitro inhibition of platelet 12-lipoxygenase at a concentration of 30 uM | B            |                   |                  |                |                |                |                   |
|          2 | CHEMBL615118 |                  0 |      684 | Autocuration |                  | Compound was evaluated for its ability to mobilize calcium in 1321NI cells                                  | F            |                   |                  |                |                |                |                   |
|          3 | CHEMBL615119 |                  0 |    15453 | Autocuration |                  |                                                                                                             | B            |                   |                  |                |                |                |                   |
|          4 | CHEMBL615120 |                  4 |    17841 | Autocuration |                  | Binding affinity against A2 adenosine receptor in bovine striatal membranes using [3H]CGS-21680             | B            |                   | Bos taurus       | 9913.0         |                |                |                   |
|          5 | CHEMBL615121 |                  1 |    17430 | Intermediate |                  | In vitro cell cytotoxicity against 143-B cell lines (Human osteosarcoma cell line)                          | F            |                   | Homo sapiens     | 9606.0         |                |                | 143B              |
|          6 | CHEMBL615122 |                  1 |    17430 | Intermediate |                  | In vitro cell cytotoxicity against 143-B cell lines (Human osteosarcoma cell line)                          | F            |                   | Homo sapiens     | 9606.0         |                |                | 143B              |
|          7 | CHEMBL615123 |                  1 |    13799 | Intermediate |                  | Cytotoxic Activity was evaluated against 143B (TK-) tumor cells                                             | F            |                   | Mus musculus     | 10090.0        |                |                | 143B              |
|          8 | CHEMBL615124 |                  1 |    17774 | Expert       |                  | In vitro cell cytotoxicity was determined against 143B cell line                                            | F            |                   | Homo sapiens     | 9606.0         |                |                | 143B              |
|          9 | CHEMBL615125 |                  1 |     3801 | Intermediate |                  | Inhibitory activity against tumor osteosarcoma cell line 143B after 72 hr continuous exposure to compound   | F            |                   | Homo sapiens     | 9606.0         |                |                | 143B              |
|         10 | CHEMBL615126 |                  1 |    17430 | Intermediate |                  | In vitro cell cytotoxicity against 143B-LTK cell lines expressed in HSV-1 TK                                | F            |                   | Homo sapiens     | 9606.0         |                |                | 143B              |

TableB:
|   ss_d | chmbl_d      |   cnfdnc_scr |   dc_d | crtd_b       | ss_ctgr   | ss_sbclllr_frctn   |    td | rltnshp_tp   |   src_d | src_ss_d   | cll_d   | b_frmt      | tss_d   | vrnt_d   |
|-------:|:-------------|-------------:|-------:|:-------------|:----------|:-------------------|------:|:-------------|--------:|:-----------|:--------|:------------|:--------|:---------|
|   7524 | CHEMBL618647 |            1 |   9866 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 | 2113.0  |          |
|   7525 | CHEMBL618648 |            1 |   9866 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 | 2113.0  |          |
|   7526 | CHEMBL618649 |            1 |   9866 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 | 2113.0  |          |
|   7527 | CHEMBL618650 |            1 |   9866 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 | 2107.0  |          |
|   7528 | CHEMBL618651 |            1 |   9866 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 | 2107.0  |          |
|   7529 | CHEMBL876497 |            1 |   9866 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 | 2107.0  |          |
|   7530 | CHEMBL618652 |            1 |   9866 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 | 2048.0  |          |
|   7531 | CHEMBL618653 |            1 |   9866 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 | 2048.0  |          |
|   7532 | CHEMBL618654 |            1 |   9866 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 | 2048.0  |          |
|   7533 | CHEMBL618655 |            1 |   6351 | Intermediate |           |                    | 50597 | N            |       1 |            |         | BAO_0000218 |         |          |



source_headers: assay_id
chembl_id
confidence_score
doc_id
curated_by
assay_category
target_headers: ss_d
chmbl_d
cnfdnc_scr
dc_d
crtd_b
ss_ctgr
column_mappings: assay_id
ss_d
chembl_id
chmbl_d
confidence_score
cnfdnc_scr
doc_id
dc_d
curated_by
crtd_b
assay_category
ss_ctgr
output: {"column_mappings": [["assay_id", "ss_d"], ["chembl_id", "chmbl_d"], ["confidence_score", "cnfdnc_scr"], ["doc_id", "dc_d"], ["curated_by", "crtd_b"], ["assay_category", "ss_ctgr"], ["description", null], ["assay_type", null], ["assay_test_type", null], ["assay_organism", null], ["assay_tax_id", null], ["assay_strain", null], ["assay_tissue", null], ["assay_cell_type", null]]}